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Reconstructing the interaction between dark energy and dark matter using
Gaussian Processes: We present a nonparametric approach to reconstruct the interaction between
dark energy and dark matter directly from SNIa Union 2.1 data using Gaussian
processes, which is a fully Bayesian approach for smoothing data. In this... | Measuring Gravitational Lensing Flexions in Abell 1689 Using an Analytic
Image Model: Measuring dark matter substructure within galaxy cluster haloes is a
fundamental probe of the Lambda-CDM model of structure formation. Gravitational
lensing is a technique for measuring the total mass distribution which is
independe... |
Searching for Cooling Signatures in Strong Lensing Galaxy Clusters:
Evidence Against Baryons Shaping the Matter Distribution in Cluster Cores: The process by which the mass density profile of certain galaxy clusters
becomes centrally concentrated enough to produce high strong lensing (SL)
cross-sections is not well u... | The Zeldovich approximation: key to understanding Cosmic Web complexity: We describe how the dynamics of cosmic structure formation defines the
intricate geometric structure of the spine of the cosmic web. The Zeldovich
approximation is used to model the backbone of the cosmic web in terms of its
singularity structure.... |
Impact of Galactic polarized emission on B-mode detection at low
multipoles: We use a model of polarized Galactic emission developed by the the Planck
collaboration to assess the impact of foregrounds on B-mode detection at low
multipoles. Our main interest is to applications of noisy polarization data and
in particu... | The Subluminous Supernova 2007qd: A Missing Link in a Family of
Low-Luminosity Type Ia Supernovae: We present multi-band photometry and multi-epoch spectroscopy of the peculiar
Type Ia supernova (SN Ia) 2007qd, discovered by the SDSS-II Supernova Survey.
It possesses physical properties intermediate to those of the p... |
Synthetic light cone catalogues of modern redshift and weak lensing
surveys with AbacusSummit: The joint analysis of different cosmological probes, such as galaxy
clustering and weak lensing, can potentially yield invaluable insights into the
nature of the primordial Universe, dark energy and dark matter. However, th... | On cosmological bias due to the magnification of shear and position
samples in modern weak lensing analyses: The magnification of galaxies in modern galaxy surveys induces additional
correlations in the cosmic shear, galaxy-galaxy lensing and clustering
observables used in modern lensing "3x2pt" analyses, due to samp... |
Abundance matching analysis of the emission line galaxy sample in the
extended Baryon Oscillation Spectroscopic Survey: We present the measurements of the small-scale clustering for the emission
line galaxy (ELG) sample from the extended Baryon Oscillation Spectroscopic
Survey (eBOSS) in the Sloan Digital Sky Survey ... | Constraining the intergalactic medium at $z\approx$ 9.1 using LOFAR
Epoch of Reionization observations: We derive constraints on the thermal and ionization states of the
intergalactic medium (IGM) at redshift $\approx$ 9.1 using new upper limits on
the 21-cm power spectrum measured by the LOFAR radio-telescope and a ... |
On the origin of the Cold Spot: In a concordant $\Lambda$ Cold Dark Matter ($\Lambda$CDM) model, large-angle
Cosmic Microwave Background (CMB) temperature anisotropy due to linear
perturbations in the local universe is not negligible. We explore a possible
role of an underdense region (void) that may cause an anomalous... | Understanding Dwarf Galaxies in order to Understand Dark Matter: Much progress has been made in recent years by the galaxy simulation
community in making realistic galaxies, mostly by more accurately capturing the
effects of baryons on the structural evolution of dark matter halos at high
resolutions. This progress has... |
Probing the Gamma-Ray Burst Rate with Trigger Simulations of the Swift
Burst Alert Telescope: The long gamma-ray burst (GRB) rate is essential for revealing the connection
between GRBs, supernovae and stellar evolution. Additionally, the GRB rate at
high redshift provides a strong probe of star formation history in t... | Multi-Wavelength Properties of Barred Galaxies in the Local Universe. I:
Virgo Cluster: We study in detail how the barred galaxy fraction varies as a function of
luminosity, HI gas mass, morphology and color in the Virgo cluster in order to
provide a well defined, statistically robust measurement of the bar fraction ... |
Coincidences between OVI and OVII Lines: Insights from High Resolution
Simulations of the Warm-Hot Intergalactic Medium: With high resolution (0.46kpc/h), adaptive mesh-refinement Eulerian
cosmological hydrodynamic simulations we compute properties of O VI and O VII
absorbers from the warm-hot intergalactic medium (W... | Far Infrared Luminosity Function of Local Galaxies in the AKARI Deep
Field South: We present the first far-infrared luminosity function in the AKARI Deep Field
South, a premier deep field of the AKARI Space Telescope, using spectroscopic
redshifts obtained with AAOmega. To date, we have found spectroscopic redshifts
... |
Producing a BOSS-CMASS sample with DES imaging: We present a sample of galaxies with the Dark Energy Survey (DES) photometry
that replicates the properties of the BOSS CMASS sample. The CMASS galaxy
sample has been well characterized by the Sloan Digital Sky Survey (SDSS)
collaboration and was used to obtain the most p... | Dark Energy Survey Year 1 results: Detection of Intra-cluster Light at
Redshift $\sim$ 0.25: Using data collected by the Dark Energy Survey (DES), we report the detection
of intracluster light (ICL) with $\sim300$ galaxy clusters in the redshift
range of 0.2-0.3. We design methods to mask detected galaxies and stars ... |
Testing the isotropy of the Universe with type Ia supernovae in a
model-independent way: In this paper, we study an anisotropic universe model with Bianchi-I metric
using Joint Light-curve Analysis (JLA) sample of type Ia supernovae (SNe Ia).
Because light-curve parameters of SNe Ia vary with different cosmological
m... | Quantifying the statistics of CMB-lensing-derived galaxy cluster mass
measurements with simulations: CMB lensing is a promising, novel way to measure galaxy cluster masses that
can be used, e.g., for mass calibration in galaxy cluster counts analyses.
Understanding the statistics of the galaxy cluster mass observable... |
GMRT 150 MHz follow up of diffuse steep spectrum radio emission in
galaxy clusters: It has been recently found that a few galaxy clusters host diffuse radio halo
emission with very steep synchrotron spectra ($\alpha$ > 1.6), which may be
classified as Ultra Steep Spectrum Radio Halos (USSRHs). USSRHs are expected in
... | Understanding Shape and Centroid Deviations in 39 Strong Lensing Galaxy
Clusters in Various Dynamical States: Through observational tests of strong lensing galaxy clusters, we can test
simulation derived structure predictions that follow from $\Lambda$ Cold Dark
Matter ($\Lambda$CDM) cosmology. The shape and centroid... |
Is there Correlation between Fine Structure and Dark Energy Cosmic
Dipoles?: We present a detailed analysis (including redshift tomography) of the cosmic
dipoles in the Keck+VLT quasar absorber and in the Union2 SnIa samples. We show
that the fine structure constant cosmic dipole obtained through the Keck+VLT
quasar ... | Gravitational Lensing of the Cosmic Neutrino Background: We study gravitational lensing of the cosmic neutrino background. This signal
is undetectable for the foreseeable future, but there is a rich trove of
information available. At least some of the neutrinos from the early universe
will be non-relativistic today, wi... |
Numerical evaluation of the tensor bispectrum in two field inflation: We evaluate the dimensionless non-Gaussianity parameter $h_{_{\rm NL}}$, that
characterizes the amplitude of the tensor bispectrum, numerically for a class
of two field inflationary models such as double inflation, hybrid inflation and
aligned natura... | Probing Neutrino Hierarchy and Chirality via Wakes: The relic neutrinos are expected to acquire a bulk relative velocity with
respect to the dark matter at low redshifts, and neutrino wakes are expected to
develop downstream of the dark matter halos. We propose a method of measuring
the neutrino mass based on this mech... |
Nonconservation of lepton current and asymmetry of relic neutrinos: The neutrino asymmetry in the early universe plasma, $n_\nu - n_{\bar \nu}$,
is calculated both before and after the electroweak phase transition (EWPT).
The leptogenesis before EWPT within the standard model is well known to be
driven by the abelian a... | A New Hybrid Framework to Efficiently Model Lines of Sight to
Gravitational Lenses: In strong gravitational lens systems, the light bending is usually dominated
by one main galaxy, but may be affected by other mass along the line of sight
(LOS). Shear and convergence can be used to approximate the contributions from
... |
Extended Photometry for the DEEP2 Galaxy Redshift Survey: A Testbed for
Photometric Redshift Experiments: This paper describes a new catalog that supplements the existing DEEP2 Galaxy
Redshift Survey photometric and spectroscopic catalogs with ugriz photometry
from two other surveys; the Canada-France-Hawaii Legacy S... | Interacting dark matter and cosmic acceleration: We study the effect of an explicit interaction between two scalar fields
components describing dark matter in the context of a recent proposal framework
for interaction. We find that, even assuming a very small coupling, it is
sufficient to explain the observational effe... |
An alternative singularity-free cosmological scenario from cusp
geometries: We study an alternative geometrical approach on the problem of classical
cosmological singularity. It is based on a generalized function $f (x, y) =
x^{2} + y^{2} = (1 - z)z^{n}$ which consists of a cusped coupled isosurface.
Such a geometry ... | Vorticity production and survival in viscous and magnetized cosmologies: We study the role of viscosity and the effects of a magnetic field on a
rotating, self-gravitating fluid, using Newtonian theory and adopting the ideal
magnetohydrodynamic approximation. Our results confirm that viscosity can
generate vorticity in... |
Radio interferometric observations of two core-dominated triple radio
sources at z>3: Aims. We selected two radio quasars (J1036+1326 and J1353+5725) based on
their 1.4-GHz radio structure, which is dominated by a bright central core and
a pair of weaker and nearly symmetric lobes at ~10" angular separation. They
are... | Constraints on Primordial Magnetic Fields from their impact on the
ionization history with Planck 2018: We update and extend our previous CMB anisotropy constraints on primordial
magnetic fields through their dissipation by ambipolar diffusion and MHD
decaying turbulence effects on the post-recombination ionization h... |
Probing Inflation with Precision Bispectra: Calculating the primordial bispectrum predicted by a model of inflation and
comparing it to what we see in the sky is very computationally intensive,
necessitating layers of approximations and limiting the models which can be
constrained. Exploiting the inherent separability ... | Influence of Low Energy Hadronic Interactions on Air-shower Simulations: Experiments measuring cosmic rays above an energy of 10^14 eV deduce the
energy and mass of the primary cosmic ray particles from air-shower
simulations. We investigate the importance of hadronic interactions at low and
high energies on the distri... |
Morphologically-Identified Merging Galaxies in the SWIRE Fields: We investigate the evolutional and environmental effects on star formation
efficiency for more than 400 merging galaxies. The ~400 merging systems, with
photometric redshifts smaller than 0.7, are obtained from a catalog of ~15000
morphologically identifi... | Cosmology and Astrophysics Using the Post-reionization HI: We discuss the prospects of using the redshifted 21~cm emission from neutral
hydrogen in the post-reionization epoch to study our universe. The main aim of
the article is to highlight the efforts of Indian scientists in this area with
the SKA in mind. It turns ... |
The Effective Field Theory of Large Scale Structures of a Fuzzy Dark
Matter Universe: Ultra-light scalar fields and their non-interacting class, the so-called
fuzzy dark matter (FDM), are candidates for dark matter, introduced to solve
the small-scale problems of the standard cold dark matter. In this paper, we
addre... | Moving Mesh Cosmology: Properties of Gas Disks: We compare the structural properties of galaxies formed in cosmological
simulations using the smoothed particle hydrodynamics (SPH) code GADGET with
those using the moving-mesh code AREPO. Both codes employ identical gravity
solvers and the same sub-resolution physics but... |
The X-ray Spectra of the Luminous LMXBs in NGC 3379: Field and Globular
Cluster Sources: From a deep multi-epoch Chandra observation of the elliptical galaxy NGC 3379
we report the spectral properties of eight luminous LMXBs (LX>1.2E38 erg/s). We
also present a set of spectral simulations, produced to aid the interpr... | On the sensitivity of weak gravitational lensing to the cosmic expansion
function: We analyse the functional derivative of the cosmic-shear power spectrum
$C_\ell^\gamma$ with respect to the cosmic expansion function. Our interest in
doing so is two-fold: (i) In view of attempts to detect minor changes of the
cosmic ... |
On the Detection of CMB B-modes from Ground at Low Frequency: The primordial CMB $B$-mode search is on the spotlight of the scientific
community due to the large amount of cosmological information that is encoded
in the primeval signal. However, the detection of this signal is challenging
from the data analysis point o... | Locating Star-Forming Regions in Quasar Host Galaxies: We present a study of the morphology and intensity of star formation in the
host galaxies of eight Palomar-Green quasars using observations with the Hubble
Space Telescope. Our observations are motivated by recent evidence for a close
relationship between black hol... |
Constraints On Holographic Cosmological Models From Gamma Ray Bursts: We use Gamma Ray Bursts (GRBs) data from Y. Wang (2008) to put additional
constraints on a set of cosmological dark energy models based on the
holographic principle. GRBs are among the most complex and energetic
astrophysical events known in the univ... | Improving cosmological covariance matrices with machine learning: Cosmological covariance matrices are fundamental for parameter inference,
since they are responsible for propagating uncertainties from the data down to
the model parameters. However, when data vectors are large, in order to
estimate accurate and precise... |
Simulating the Universe with MICE: The abundance of massive clusters: We introduce a new set of large N-body runs, the MICE simulations, that
provide a unique combination of very large cosmological volumes with good mass
resolution. They follow the gravitational evolution of ~ 8.5 billion particles
(2048^3) in volumes ... | CS, HC3N and CH3CCH multi-line analyses towards starburst galaxies. The
evolution of cloud structures in the central regions of galaxies: We aim to study the properties of the dense molecular gas towards the inner
few 100 pc of four nearby starburst galaxies dominated both by photo
dissociation regions (M82) and larg... |
Inflationary cosmology with nonlinear dispersion relations: We present a technique, {\em the uniform asymptotic approximation}, to
construct accurate analytical solutions of the linear perturbations of
inflation after quantum effects of the early universe are taken into account,
for which the dispersion relations gener... | Cosmological Implications of Axion-Matter Couplings: Axions and other light particles appear ubiquitously in physics beyond the
Standard Model, with a variety of possible couplings to ordinary matter.
Cosmology offers a unique probe of these particles as they can thermalize in
the hot environment of the early universe ... |
Constraints on the cosmological coupling of black holes from Gaia: Recent work has suggested that black holes (BHs) could be cosmologically
coupled to the accelerated expansion of the universe, potentially becoming a
candidate for dark energy. This would imply BH mass growth following the
cosmological expansion, with t... | A Stable Finite-Volume Method for Scalar-Field Dark Matter: We describe and test a family of new numerical methods to solve the
Schrodinger equation in self-gravitating systems, e.g. Bose-Einstein
condensates or 'fuzzy'/ultra-light scalar field dark matter. The methods are
finite-volume Godunov schemes with stable, hig... |
Deep Chandra observation of the galaxy cluster WARPJ1415.1+3612 at z=1:
an evolved cool-core cluster at high-redshift: Using the deepest (370 ksec) Chandra observation of a high-redshift galaxy
cluster, we perform a detailed characterization of the intra-cluster medium
(ICM) of WARPJ1415.1+3612 at z=1.03. We also exp... | AMiBA Wideband Analog Correlator: A wideband analog correlator has been constructed for the Yuan-Tseh Lee Array
for Microwave Background Anisotropy. Lag correlators using analog multipliers
provide large bandwidth and moderate frequency resolution. Broadband IF
distribution, backend signal processing and control are de... |
Constraints on the low-mass end of the mass-metallicity relation at
z=1-2 from lensed galaxies: We present multi-wavelength imaging and near-IR spectroscopy for ten
gravitationally lensed galaxies at 0.9<z<2.5 selected from a new, large sample
of strong lens systems in the Sloan Digital Sky Survey (SDSS) DR7. We deri... | Cross-Correlation of Cosmological Birefringence with CMB Temperature: Theories for new particle and early-Universe physics abound with
pseudo-Nambu-Goldstone fields that arise when global symmetries are
spontaneously broken. The coupling of these fields to the Chern-Simons term of
electromagnetism may give rise to cosm... |
Intermediate inflation under the scrutiny of recent data: We use the flow equations to determine the different hierarchy Hubble
parameters as a function of the number of e-folds for intermediate models in
single-field inflation. The obtained expressions allow us to determine at
second order in the hierarchy Hubble para... | The VIMOS Public Extragalactic Redshift Survey (VIPERS). Exploring the
dependence of the three-point correlation function on stellar mass and
luminosity at 0.5<z<1.1: The three-point correlation function (3PCF) is a powerful probe to
investigate the clustering of matter in the Universe in a complementary way
with r... |
Detecting coalescences of intermediate-mass black holes in globular
clusters with the Einstein Telescope: We discuss the capability of a third-generation ground-based detector such as
the Einstein Telescope to detect mergers of intermediate-mass black holes that
may have formed through runaway stellar collisions in g... | A Big Ring on the Sky: We present the discovery of `A Big Ring on the Sky' (BR), the second
ultra-large-scale structure (uLSS) found in MgII-absorber catalogues, following
the previously reported Giant Arc (GA). In cosmological terms the BR is close
to the GA - at the same redshift $z \sim 0.8$ and with a separation on... |
Further evidence for large central mass-to-light ratios in massive
early-type galaxies: We studied the stellar populations, distribution of dark matter, and
dynamical structure of a sample of 25 early-type galaxies in the Coma and Abell
262 clusters. We derived dynamical mass-to-light ratios and dark matter
densities... | Cosmic String Loop Microlensing: Cosmic superstring loops within the galaxy microlens background point sources
lying close to the observer-string line of sight. For suitable alignments,
multiple paths coexist and the (achromatic) flux enhancement is a factor of
two. We explore this unique type of lensing by numerically... |
Lyman-Alpha Emitting Galaxies as a Probe of Reionization: Large-Scale
Bubble Morphology and Small-Scale Absorbers: The visibility of LyA emitting galaxies during the Epoch of Reionization is
controlled by both diffuse HI patches in large-scale bubble morphology and
small-scale absorbers. To investigate the impact on ... | Newtonian Hydrodynamics with General Relativistic Pressure: We present the general relativistic pressure correction terms in Newtonian
hydrodynamic equations to the nonlinear order: these are equations
(\ref{mass-conservation-Mink})-(\ref{Poisson-eq-Mink}). The derivation is made
in the zero-shear gauge based on the fu... |
Small Angular Scale Measurements of the CMB Temperature Power Spectrum
from QUaD: We present measurements of the cosmic microwave background (CMB) radiation
temperature anisotropy in the multipole range 2000<ell<3000 from the QUaD
telescope's second and third observing seasons. After masking the brightest
point sourc... | Machine-learning computation of distance modulus for local galaxies: Quickly growing computing facilities and an increasing number of
extragalactic observations encourage the application of data-driven approaches
to uncover hidden relations from astronomical data. In this work we raise the
problem of distance reconstru... |
Primordial Non-Gaussianity in Models with Dark Matter Isocurvature
Fluctuations: We investigate primordial non-Gaussianity and dark matter isocurvature
fluctuations in the modulated reheating and the curvaton scenarios. In these
scenarios, large non-Gaussianity can be generated, on the other hand, depending
on how da... | Origin and Modelling of Cold Dark Matter Halo Properties: IV. Triaxial
Ellipticity: This paper has been withdrawn owing a re-arrangement of two previously
submitted papers. The new version of the theoretical work on the triaxial shape
of dark matter haloes can be found at the ArXiv astro-ph list (CO) as article
1104.... |
GECO: Galaxy Evolution COde - A new semi-analytical model of galaxy
formation: We present a new semi-analytical model of galaxy formation, GECO (Galaxy
Evolution COde), aimed at a better understanding of when and how the two
processes of star formation and galaxy assembly have taken place. Our model is
structured int... | Multiwavelength campaign on Mrk 509 VII. Relative abundances of the warm
absorber: Context. The study of abundances in the nucleus of active galaxies allows us
to investigate the evolution of abundance by comparing local and higher
redshift galaxies. However, the methods used so far have substantial drawbacks
or rath... |
A Uniform Type Ia Supernova Distance Ladder with the Zwicky Transient
Facility: Absolute Calibration Based on the Tip of the Red Giant Branch
(TRGB) Method: The current Cepheid-calibrated distance ladder measurement of $H_0$ is
reported to be in tension with the values inferred from the cosmic microwave
background ... | Spatially Resolved Emission of a High Redshift DLA Galaxy with the
Keck/OSIRIS IFU: We present the first Keck/OSIRIS infrared IFU observations of a high redshift
damped Lyman-alpha (DLA) galaxy detected in the line of sight to a background
quasar. By utilizing the Laser Guide Star Adaptive Optics (LGSAO) to reduce th... |
Crossing the phantom divide with a classical Dirac field: In this paper we consider a spatially flat Friedmann-Robertson-Walker (FRW)
cosmological model with cosmological constant, containing a stiff fluid and a
classical Dirac field. The proposed cosmological scenario describes the
evolution of effective dark matter a... | The nuclear starburst in Arp 299-A: From the 5.0 GHz VLBI radio
light-curves to its core-collapse supernova rate: The nuclear region of the Luminous Infra-red Galaxy Arp 299-A hosts a recent
($\simeq 10$ Myr), intense burst of massive star formation which is expected to
lead to numerous core-collapse supernovae (CCSN... |
Magnetic Fields from QCD Phase Transitions: We study the evolution of QCD phase transition-generated magnetic fields in
freely decaying MHD turbulence of the expanding Universe. We consider a
magnetic field generation model that starts from basic non-perturbative QCD
theory and predicts stochastic magnetic fields with ... | Cosmic bulk flows on 50 {h}^{-1}Mpc scales: A Bayesian hyper-parameter
method and multishells likelihood analysis: It has been argued recently that the galaxy peculiar velocity field provides
evidence of excessive power on scales of $50\hmpc$, which seems to be
inconsistent with the standard $\Lambda$CDM cosmological... |
Blue E/S0 galaxies: merger remnants or disk rebuilding galaxies?: This paper has been withdrawn A new version is in preparation and will be
soon available. | Star forming galaxies in the Hercules cluster: Halpha imaging of A2151: This paper presents the first results of an Halpha imaging survey of galaxies
in the central regions of the A2151 cluster. A total of 50 sources were
detected in Halpha. The morphologies of the 43 H$\alpha$ selected galaxies
range from grand design... |
Inelastic Dark Matter and DAMA/LIBRA: An Experimentum Crucis: The DAMA/LIBRA collaboration has detected an annual modulation of the recoil
rate in NaI crystals with the phase expected for WIMP scattering events. This
signal is dramatically inconsistent with upper limits from other experiments
for elastically scattering... | Impact of the Relative Motion between the Dark Matter and Baryons on the
First Stars: Recently the initial supersonic relative velocity between the dark matter and
baryons was shown to have an important effect on galaxy formation at high
redshift. We study the impact of this relative motion on the distribution of
the... |
Multi-field inflation with large scalar fluctuations: non-Gaussianity
and perturbativity: Recently multi-field inflation models that can produce large scalar
fluctuations on small scales have drawn a lot of attention, primarily because
they could lead to primordial black hole production and generation of large
second... | Electromagnetic plasma waves in dark energy cosmology: We explore electromagnetic wave modes that can exist in a cosmological plasma
dominated by dark energy due to a cosmological constant. It is found that, in
the cold and hot plasma cases, electromagnetic plasma wave modes can be found
exactly. The effect of this cos... |
Testing the EoS of dark matter with cosmological observations: We explore the cosmological constraints on the parameter w_dm of the dark
matter barotropic equation of state (EoS) to investigate the "warmness" of the
dark matter fluid. The model is composed by the dark matter and dark energy
fluids in addition to the ra... | The Canada-France High-z Quasar Survey: nine new quasars and the
luminosity function at redshift 6: We present discovery imaging and spectroscopy for nine new z ~ 6 quasars
found in the Canada-France High-z Quasar Survey (CFHQS) bringing the total
number of CFHQS quasars to 19. By combining the CFHQS with the more lu... |
Forecast constraints on Anisotropic Stress in Dark Energy using
gravitational-waves: It is always interesting to investigate how well can a future experiment
perform with respect to others (present or future ones). Cosmology is really an
exciting field where a lot of puzzles are still unknown. In this article we
cons... | Using Spectral Flux Ratios to Standardize SN Ia Luminosities: We present a new method to standardize Type Ia supernova (SN Ia) luminosities
to ~<0.13 magnitudes using flux ratios from a single flux-calibrated spectrum
per SN. Using Nearby Supernova Factory spectrophotomery of 58 SNe Ia, we
performed an unbiased search ... |
Discovery of z~8 Galaxies in the HUDF from ultra-deep WFC3/IR
Observations: We utilize the newly-acquired, ultra-deep WFC3/IR observations over the HUDF
to search for star-forming galaxies at z~8-8.5, only 600 million years from
recombination, using a Y_{105}-dropout selection. The new 4.7 arcmin**2 WFC3/IR
observati... | Particle reacceleration by compressible turbulence in galaxy clusters:
effects of reduced mean free path: Direct evidence for in situ particle acceleration mechanisms in the
inter-galactic-medium (IGM) is provided by the diffuse Mpc--scale synchrotron
emissions observed from galaxy clusters. It has been proposed that... |
A dearth of dark matter in strong gravitational lenses: I show that the lensing masses of the SLACS sample of strong gravitational
lenses are consistent with the stellar masses determined from population
synthesis models using the Salpeter IMF. This is true in the context of both
General Relativity and modified Newtoni... | Hunting Axion Dark Matter with Protoplanetary Disk Polarimetry: We find that the polarimetric observations of protoplanetary disks are useful
to search for ultra-light axion dark matter. Axion dark matter predicts the
rotation of the linear polarization plane of propagating light, and
protoplanetary disks are ideal tar... |
Preheating after multifield inflation with nonminimal couplings, II:
Resonance Structure: This is the second in a series of papers on preheating in inflationary models
comprised of multiple scalar fields coupled nonminimally to gravity. In this
paper, we work in the rigid-spacetime approximation and consider field
tr... | Modelling the large scale structure of the Universe as a function of
cosmology and baryonic physics: We present and test a framework that models the three-dimensional
distribution of mass in the Universe as a function of cosmological and
astrophysical parameters. Our approach combines two different techniques: a
resc... |
Probing solutions to the $S_8$ tension with galaxy clustering: The current discrepancy between the CMB and weak lensing measurements of the
amplitude of matter fluctuations, the so-called $S_8$ tension, has attracted a
great deal of recent attention, as it may show a crack in the $\Lambda$CDM
model of cosmology. We rev... | Four direct measurements of the fine-structure constant 13 billion years
ago: Observations of the redshift z=7.085 quasar J1120+0641 have been used to
search for variations of the fine structure constant, alpha, over the redshift
range 5.5 to 7.1. Observations at z=7.1 probe the physics of the universe when
it was on... |
Predictions for the 21cm-galaxy cross-power spectrum observable with
LOFAR and Subaru: The 21cm-galaxy cross-power spectrum is expected to be one of the promising
probes of the Epoch of Reionization (EoR), as it could offer information about
the progress of reionization and the typical scale of ionized regions at
dif... | Very Large Array observations of the 8 o'clock arc lens system: Radio
emission and a limit on the star-formation rate: The 8 o'clock arc is a gravitationally lensed Lyman Break Galaxy (LBG) at
redshift z=2.73 that has a star-formation rate (SFR) of 270 solar-mass/year
(derived from optical and near-infrared spectrosc... |
Constraints on cosmic hemispherical power anomalies from quasars: Recent analyses of the cosmic microwave background (CMB) maps from the WMAP
satellite have uncovered evidence for a hemispherical power anomaly, i.e. a
dipole modulation of the CMB power spectrum at large angular scales with an
amplitude of +/-14 percent... | Galaxy pairs in the Sloan digital sky survey - VII: The merger --
luminous infra-red galaxy connection: We use a sample of 9397 low z galaxies with a close companion to investigate
the connection between mergers and luminous infra-red (IR) galaxies (LIRGs).
The pairs are selected from the SDSS and have projected sepa... |
Clustering dark energy and halo abundances: Within the standard paradigm, dark energy is taken as a homogeneous fluid
that drives the accelerated expansion of the universe and does not contribute
to the mass of collapsed objects such as galaxies and galaxy clusters. The
abundance of galaxy clusters -- measured through ... | Metal Transport to the Gaseous Outskirts of Galaxies: We present a search for outlying HII regions in the extended gaseous
outskirts of nearby (D < 40 Mpc) galaxies, and subsequent multi-slit
spectroscopy used to obtain the HII region nebular oxygen abundances. The
galaxies in our sample have extended HI disks and/or i... |
Asymmetric condensed dark matter: We explore the viability of a boson dark matter candidate with an asymmetry
between the number densities of particles and antiparticles. A simple thermal
field theory analysis confirms that, under certain general conditions, this
component would develop a Bose-Einstein condensate in th... | A simplified structure for the second order cosmological perturbation
equations: Increasingly accurate observations of the cosmic microwave background and the
large scale distribution of galaxies necessitate the study of nonlinear
perturbations of Friedmann-Lemaitre cosmologies, whose equations are
notoriously compli... |
Mapping the properties of blue compact dwarf galaxies: integral field
spectroscopy with PMAS: (Abridged) We perform integral field spectroscopy of a sample of Blue compact
dwarf (BCD) galaxies with the aim of analyzing their morphology, the spatial
distribution of some of their physical properties (excitation, extinc... | AMICO galaxy clusters in KiDS-DR3: the impact of estimator statistics on
the luminosity-mass scaling relation: As modern-day precision cosmology aims for statistical uncertainties of the
percent level or lower, it becomes increasingly important to reconsider
estimator assumptions at each step of the process, and thei... |
Evolution and Distribution of Magnetic Fields from AGNs in Galaxy
Clusters II. The Effects of Cluster Size and Dynamical State: Theory and simulations suggest that magnetic fields from radio jets and lobes
powered by their central super massive black holes can be an important source
of magnetic fields in the galaxy c... | Search for dark energy potentials in quintessence theory: The time evolution of the equation of state $w$ for quintessence models with
a scalar field as dark energy is studied up to the third derivative
($d^3w/da^3$) with respect to the scale factor $a$, in order to predict the
future observations and specify the scala... |
A Method for 21cm Power Spectrum Estimation in the Presence of
Foregrounds: 21cm tomography promises to be a powerful tool for estimating cosmological
parameters, constraining the epoch of reionization, and probing the so-called
dark ages. However, realizing this promise will require the extraction of a
cosmological ... | Supernovae without host galaxy? - Hypervelocity stars in foreign
galaxies: Harvesting the SAI supernova catalog, we search for SNe that apparently do
not occur within a distinct host galaxy but lie a great distance apart from
their assigned host galaxy. Assuming two possible explanations for this
host-lessness of a f... |
Galaxy Zoo: A sample of blue early-type galaxies at low redshift: We report the discovery of a population of nearby, blue early-type galaxies
with high star formation rates (0.5 < SFR < 50 Msun/yr). They are identified by
their visual morphology as provided by Galaxy Zoo for SDSS DR6 and their u-r
colour. We select a v... | Novel Adaptive softening for collisionless N-body simulations:
Eliminating spurious halos: We describe a NOVel form of Adaptive softening (NovA) for collisionless
$N$-body simulations, implemented in the Ramses adaptive mesh refinement code.
We introduce a refinement criterion that the particle distribution within ea... |
Priors on red galaxy stochasticity from hybrid effective field theory: We investigate the stochastic properties of typical red galaxy samples in a
controlled numerical environment. We use Halo Occupation Distribution (HOD)
modelling to create mock realizations of three separate bright red galaxy
samples consistent with... | Stable Heating of Cluster Cooling Flows by Cosmic-Ray Streaming: We study heating of cool cores in galaxy clusters by cosmic-ray (CR)
streaming using numerical simulations. In this model, CRs are injected by the
central active galactic nucleus (AGN) and move outward with Alfven waves. The
waves are excited by the strea... |
Metallicity as a source of dispersion in the SNIa bolometric light curve
luminosity-width relationship: The recognition that the metallicity of Type Ia supernova (SNIa) progenitors
might bias their use for cosmological applications has led to an increasing
interest in its role on the shaping of SNIa light curves. We ... | Influence of Unobservable Modes on Correlation Functions during
Inflation: Coupling between sub- and super-Hubble modes can affect the locally observed
statistics of our universe. In the context of Quasi-Single Field Inflation, we
can compute correlation functions and derive the influence of those
unobservable modes ... |
Observational Probes of Cosmic Acceleration: The accelerating expansion of the universe is the most surprising
cosmological discovery in many decades, implying that the universe is dominated
by some form of "dark energy" with exotic physical properties, or that
Einstein's theory of gravity breaks down on cosmological s... | What do observations of the Lyman-alpha fraction tell us about
reionization?: An appealing approach for studying the reionization history of the Universe
is to measure the redshift evolution of the Lyman-alpha fraction, the
percentage of Lyman-break selected galaxies that emit appreciably in the
Ly-alpha line. This f... |
Nuclear and Extended Spectra of NGC 1068 - II: Near-Infrared Stellar
Population Synthesis: We performed stellar population synthesis on the nuclear and extended regions
of NGC 1068 by means of near-infrared spectroscopy to disentangle their
spectral energy distribution components. This is the first time that such a
t... | Inflating a chain of x-ray deficient bubbles by a single jet activity
episode: We show that a continuous jet with time-independent launching properties can
inflate a chain of close and overlapping X-ray deficient bubbles. Using the
numerical code PLUTO we run 2.5D (i.e. spherical coordinate system with
cylindrical sy... |
On the stellar populations of massive galaxies: In this Letter, we analyse the predicted physical properties of massive
galaxies, in the framework of recent semi-analytic models of galaxy formation.
All models considered account for winds driven by supernovae explosions and
suppression of gas condensation at the centre... | Weak lensing measurement of the mass-richness relation using the SDSS
database: We study the mass-richness relation using galaxy catalogues and images from
the Sloan Digital Sky Survey. We use two independent methods, in the first one,
we calibrate the scaling relation with weak-lensing mass estimates. In the
second ... |
Observational constraints of diffusive dark-fluid cosmology: In this work, we consider an interacting dark-fluid cosmological model in
which energy exchange between dark matter and dark energy occurs through
diffusion. After solving the background expansion history for a late-time
universe, we attempt to constrain the ... | Spectroscopy in the Era of LSST: This report summarizes the results of the 'Spectroscopy in the Era of LSST'
workshop held April 11-12, 2013 in Tucson, Arizona. At the workshop, there were
breakout sessions covering four broad science topics. These were: time domain
science, Galactic structure and stellar populations, ... |
Chemical properties in the most distant radio galaxy: We present a deep optical spectrum of TN J0924-2201, the most distant radio
galaxy at z = 5.19, obtained with FOCAS on the Subaru Telescope. We
successfully detect, for the first time, the CIV1549 emission line from the
narrow-line region (NLR). In addition to the e... | Lessons from the first multiply imaged supernova: A revised
Light-Traces-Mass strong lensing model for the galaxy cluster MACS
J1149.5+2223: Our light-traces-mass (LTM) strong-lensing model for MACS J1149.5+2223 has
played several key roles over the last decade: it aided the identification of
multiple images in thi... |
Signatures of Small-scale Structure of the Pre-reionization
Intergalactic Medium in $z\gtrsim7$ Quasar Proximity Zones: The small-scale structure of baryons in the intergalactic medium is
intimately linked to their past thermal history. Prior to the $\gtrsim10^4$ K
photoheating during the epoch of reionization, cold ... | Suite of Hydrodynamical Simulations for the Lyman-Alpha Forest with
Massive Neutrinos: The signature left in quasar spectra by the presence of neutral hydrogen in
the Universe allows one to constrain the sum of the neutrino masses with
improved sensitivity, with respect to laboratory experiments, and may shed a
new l... |
Massive Primordial Black Holes as Dark Matter and their detection with
Gravitational Waves: Massive Primordial Black Holes (MPBH) can be formed after inflation due to
broad peaks in the primordial curvature power spectrum that collapse
gravitationally during the radiation era, to form clusters of black holes that
mer... | The Dark Energy Spectroscopic Instrument: One-dimensional power spectrum
from first Lyman-$α$ forest samples with Fast Fourier Transform: We present the one-dimensional Lyman-$\alpha$ forest power spectrum
measurement using the first data provided by the Dark Energy Spectroscopic
Instrument (DESI). The data sample co... |
Narrowband Lyman-Continuum Imaging of Galaxies at z ~ 2.85: We present results from a survey for z~2.85 Lyman-Continuum (LyC) emission in
the HS1549+1933 field and place constraints on the amount of ionizing radiation
escaping from star-forming galaxies. Using a custom narrowband filter (NB3420)
tuned to wavelengths ju... | Constraining the Halo Mass of Damped Ly$α$ Absorption Systems
(DLAs) at $z=2-3.5$ using the Quasar-CMB Lensing Cross-correlation: We study the cross correlation of damped Ly$\alpha$ systems (DLAs) and their
background quasars, using the most updated DLA catalog and the Planck 2018 CMB
lensing convergence field. Our m... |
The Effects of Dark Matter Annihilation on Cosmic Reionization: We revisit the possibility of constraining the properties of dark matter (DM)
by studying the epoch of cosmic reionization. Previous studies have shown that
DM annihilation was unlikely to have provided a large fraction of the photons
that ionized the univ... | Discovery of a giant HI tail in the galaxy group HCG 44: We report the discovery of a giant HI tail in the intra-group medium of HCG
44 as part of the Atlas3D survey. The tail is ~300 kpc long in projection and
contains ~5x10^8 M_sun of HI. We detect no diffuse stellar light at the
location of the tail down to ~28.5 ma... |
A high-dispersion molecular gas component in nearby galaxies: We present a comprehensive study of the velocity dispersion of the atomic
(HI) and molecular (H2) gas components in the disks (R < R25) of a sample of 12
nearby spiral galaxies with moderate inclinations. Our analysis is based on
sensitive high resolution da... | CIV Emission as a Probe of Accretion Disk Winds: We present a brief description of a model for the broad emission line region
(BELR) in quasars, which is supported by analysis of CIV and other emission
lines in the spectra of high-z SDSS quasars. Specifically we consider a
two-component BELR with a disk and wind where ... |
Cosmological constraints on Hořava gravity revised in light of
GW170817 and GRB170817A and the degeneracy with massive neutrinos: We revise the cosmological bounds on Ho\v{r}ava gravity taking into accounts
the stringent constraint on the speed of propagation of gravitational waves
from GW170817 and GRB170817A. In li... | Ram pressure stripping of disk galaxies in galaxy clusters: While galaxies move through the intracluster medium of their host cluster,
they experience a ram pressure which removes at least a significant part of
their interstellar medium. This ram pressure stripping appears to be especially
important for spiral galaxies... |
The 3.3 micron PAH Emission as a Star Formation Rate Indicator: Polycyclic Aromatic Hydrocarbon (PAH) emission features dominate the
mid-infrared spectra of star-forming galaxies and can be useful to calibrate
star formation rates and diagnose ionized states of grains. However, the PAH
3.3 micron feature has not been s... | Turbulence and Dynamo in Galaxy Cluster Medium: Implications on the
Origin of Cluster Magnetic Fields: We present self-consistent cosmological magnetohydrodynamic (MHD) simulations
that simultaneously follow the formation of a galaxy cluster and the magnetic
field ejection by an active galactic nucleus (AGN). We find... |
Radio-continuum jets around the peculiar galaxy pair ESO 295-IG022: We report new radio-continuum observations with the Australia Telescope
Compact Array (ATCA) of the region surrounding the peculiar galaxy pair ESO
295-IG022, at the centre of the poor cluster Abell S0102. We observed this
cluster at wavelengths of lam... | Assessing Radiation Pressure as a Feedback Mechanism in Star-Forming
Galaxies: Radiation pressure from the absorption and scattering of starlight by dust
grains may be an important feedback mechanism in regulating star-forming
galaxies. We compile data from the literature on star clusters, star-forming
subregions, no... |
The ACS Fornax Cluster Survey VII. Half-Light Radii of Globular Clusters
in Early-Type Galaxies: We measure the half-light radii of globular clusters (GCs) in 43 galaxies
from the ACS Fornax Cluster Survey (ACSFCS). We use these data to extend
previous work in which the environmental dependencies of the half-light ra... | Radio-emission of axion stars: We study parametric instability of compact axion dark matter structures
decaying to radiophotons. Corresponding objects - Bose (axion) stars, their
clusters, and clouds of diffuse axions - form abundantly in the
postinflationary Peccei-Quinn scenario. We develop general description of
par... |
Large pre-inflationary thermal density perturbations: In some versions of the theory of inflation, it is assumed that before
inflation began the universe was in a Friedmann-Robertson-Walker (FRW) stage,
with the energy density dominated by massless particles. The origin of the
nearly scale-invariant density perturbatio... | Path Integral Marginalization for Cosmology: Scale Dependent Galaxy Bias
& Intrinsic Alignments: We present a path-integral likelihood formalism that extends parameterized
likelihood analyses to include continuous functions. The method finds the
maximum likelihood point in function-space, and marginalizes over all po... |
Parity-violating and anisotropic correlations in pseudoscalar inflation: A pseudo-scalar inflaton field can have interesting phenomenological
signatures associated with parity violation. The existing analyses of these
signatures typically assume statistical isotropy. In the present work we
instead investigate the possi... | Rayleigh-Taylor Instability at Ionization Fronts: Perturbation Analysis: The linear growth rate of the Rayleigh-Taylor instability (RTI) at ionization
fronts is investigated via perturbation analysis in the limit of incompressible
fluids. In agreement with previous numerical studies is found that absorption
of ionizing... |
Baryon-photon interactions in Resummed Kinetic Field Theory: We explore how interactions between baryons and photons can be incorporated
into Kinetic Field Theory (KFT), a description of cosmic structure formation
based on classical Hamiltonian particle dynamics. In KFT, baryons are described
as effective mesoscopic pa... | Infrared Spectroscopy of Halos of Edge-on Galaxies: We present a study of ionized gas, PAHs, and molecular hydrogen emission in
the halos of three edge-on galaxies, NGC 891, NGC 5775 and NGC 3044, based on
10-20 micron Spitzer Space Telescope spectra. The [Ne III]/[Ne II] ratio, an
excellent measure of radiation hardne... |
Excursion set peaks: the role of shear: Recent analytical work on the modelling of dark halo abundances and
clustering has demonstrated the advantages of combining the excursion set
approach with peaks theory. We extend these ideas and introduce a model of
excursion set peaks that incorporates the role of initial tidal... | Seeing the First Supernovae at the Edge of the Universe with JWST: The first stars ended the cosmic Dark Ages and created the first heavy
elements necessary for the formation of planets and life. The properties of
these stars remain uncertain, and it may be decades before individual Pop III
stars are directly observed.... |
Stellar mass Primordial Black Holes as Cold Dark Matter: Primordial Black Holes (PBHs) might have formed in the early Universe due to
the collapse of density fluctuations. PBHs may act as the sources for some of
the gravitational waves recently observed. We explored the formation scenarios
of PBHs of stellar mass, taki... | Model-independent constraints on cosmic curvature: implication from the
future gravitational wave observation DECIGO: A model-independent test of the cosmic curvature parameter $\Omega_k$ is very
important in cosmology. In order to estimate cosmic curvature from cosmological
probes like standard candles, one has to b... |
Towards a realistic solution of the cosmological constant fine-tuning
problem by Higgs inflation: Why the cosmological constant $\Lambda$ observed today is so much smaller
than the Planck scale or why the universe is accelerating at present? This is
so-called the cosmological constant fine-tuning problem. In this pap... | Limits on Second-Order Non-Gaussianity from Minkowski Functionals of
WMAP Data: We analyze non-Gaussianity (NG) due to the primordial bispectrum and
trispectrum using CMB temperature maps of WMAP 7-year data. We first apply the
perturbative formulae of Minkowski functionals up to second-order NG derived by
Matsubara ... |
The Fundamental Plane of Damped Lyman Alpha Systems: Using a sample of 100 H I - selected damped Lyman alpha (DLA) systems,
observed with the High Resolution Echelle Spectrometer on the Keck I telescope,
we present evidence that the scatter in the well-studied correlation between
the redshift and metallicity of a DLA i... | Reconstructing inflationary paradigm within Effective Field Theory
framework: In this paper my prime objective is to analyze the constraints on a
sub-Planckian excursion of a single inflaton field within Effective Field
Theory framework in a model independent fashion. For a generic single field
inflationary potential... |
Dust temperature and CO-to-H2 conversion factor variations in the SFR-M*
plane: Deep Herschel imaging and 12CO(2-1) line luminosities from the IRAM PdBI are
combined for a sample of 17 galaxies at z>1 from the GOODS-N field. The sample
includes galaxies both on and above the main sequence (MS) traced by
star-forming ... | Why are some galaxy clusters underluminous? The very low concentration
of the CL2015 mass profile: Our knowledge of the variety of galaxy clusters has been increasing in the
last few years thanks to our progress in understanding the severity of
selection effects on samples. To understand the reason for the observed
v... |
A Spitzer IRAC Measure of the Zodiacal Light: The dominant non-instrumental background source for space-based infrared
observatories is the zo- diacal light. We present Spitzer Infrared Array Camera
(IRAC) measurements of the zodiacal light at 3.6, 4.5, 5.8, and 8.0 {\mu}m,
taken as part of the instrument calibrations.... | Testing galaxy formation scenarios with a new mass estimator: We present the recently derived Wolf et al. (2009) mass estimator, which is
applicable for spherical pressure-supported stellar systems spanning over ten
orders of magnitude in luminosity, as a tool to test galaxy formation theories.
We show that all of the ... |
NGC 1300 Dynamics: III. Orbital analysis: We present the orbital analysis of four response models, that succeed in
reproducing morphological features of NGC 1300. Two of them assume a planar
(2D) geometry with $\Omega_p$=22 and 16 \ksk respectively. The two others
assume a cylindrical (thick) disc and rotate with the s... | Constraining Cosmology with Big Data Statistics of Cosmological Graphs: By utilizing large-scale graph analytic tools implemented in the modern Big
Data platform, Apache Spark, we investigate the topological structure of
gravitational clustering in five different universes produced by cosmological
$N$-body simulations ... |
Deformed Distance Duality Relations and Supernovae Dimming: The basic cosmological distances are linked by the Etherington cosmic
distance duality relation, $\eta (z) = D_{L}(z)(1+z)^{-2}/D_{A}(z) \equiv 1$,
where $D_{L}$ and $D_{A}$ are, respectively, the luminosity and angular
diameter distances. In order to test its... | On the Segregation of Dark Matter Substructure: We present the first comprehensive analysis of the segregation of dark matter
subhaloes in their host haloes. Using numerical simulations, we examine the
segregation of twelve different subhalo properties with respect to both orbital
energy and halo-centric radius (in rea... |
Creating perturbations from a decaying field during inflation: Typically the fluctuations generated from a decaying field during inflation
do not contribute to the large scale structures. In this paper we provide an
example where it is possible for a field which slowly rolls and then decays
during inflation to create a... | Fundamental Physics from Future Weak-Lensing Calibrated
Sunyaev-Zel'dovich Galaxy Cluster Counts: Future high-resolution measurements of the cosmic microwave background (CMB)
will produce catalogs of tens of thousands of galaxy clusters through the
thermal Sunyaev-Zel'dovich (tSZ) effect. We forecast how well differe... |
Quasar Feedback: More Bang for Your Buck: We propose a two-stage model for the effects of feedback from a bright quasar
on the cold gas in a galaxy. It is difficult for feedback from near the
accretion disk to directly impact dense molecular clouds at ~kpc. But if such
feedback can drive a weak wind or outflow in the h... | Multifrequency Radio Observations of a SNR in the LMC. The Case of SNR
J0527-6549 (DEM l204): We present a detailed study and results of new Australia Telescope Compact
Array (ATCA) observations of supernova remnant, SNR J0527-6549. This Large
Magellanic Cloud (LMC) ob ject follows a typical supernova remnant (SNR)
h... |
Incorporating Astrophysical Systematics into a Generalized Likelihood
for Cosmology with Type Ia Supernovae: Traditional cosmological inference using Type Ia supernovae (SNeIa) have used
stretch- and color-corrected fits of SN Ia light curves and assumed a resulting
fiducial mean and symmetric intrinsic dispersion fo... | Probing the inflaton: Small-scale power spectrum constraints from
measurements of the CMB energy spectrum: In the early Universe, energy stored in small-scale density perturbations is
quickly dissipated by Silk-damping, a process that inevitably generates mu- and
y-type spectral distortions of the cosmic microwave ba... |
The Impact of Modeling Errors on Interferometer Calibration for 21 cm
Power Spectra: We study the impact of sky-based calibration errors from source mismodeling
on 21\,cm power spectrum measurements with an interferometer and propose a
method for suppressing their effects. While emission from faint sources that
are n... | SPIDERS: the spectroscopic follow-up of X-ray selected clusters of
galaxies in SDSS-IV: SPIDERS (The SPectroscopic IDentification of eROSITA Sources) is a program
dedicated to the homogeneous and complete spectroscopic follow-up of X-ray AGN
and galaxy clusters over a large area ($\sim$7500 deg$^2$) of the extragalac... |
Simulation-based inference of deep fields: galaxy population model and
redshift distributions: Accurate redshift calibration is required to obtain unbiased cosmological
information from large-scale galaxy surveys. In a forward modelling approach,
the redshift distribution n(z) of a galaxy sample is measured using a
p... | Gravitational lens candidates in the E-CDFS: We report ten lens candidates in the E-CDFS from the GEMS survey. Nine of the
systems are new detections and only one of the candidates is a known lens
system. For the most promising five systems including the known lens system, we
present results from preliminary lens mass ... |
Determination of dark matter type by X-ray sources statistics: The current cosmological model includes cold dark matter, which consists of
massive nonrelativistic particles. There are also some observational and
theoretical evidences for warm dark matter. The existence of warm DM can be
examined by measuring of the gal... | Nucleosynthetic signatures of primordial origin around supermassive
black holes: If primordial black holes (PBHs) seeded the supermassive black holes (SMBHs)
at the centers of high-redshift quasars, then the gas surrounding these black
holes may reveal nucleosynthetic clues to their primordial origins. We present
pre... |
Reconstructing the primordial power spectrum from the CMB: We propose a straightforward and model independent methodology for
characterizing the sensitivity of CMB and other experiments to wiggles,
irregularities, and features in the primordial power spectrum. Assuming that
the primordial cosmological perturbations are... | Cosmic Topology of Polyhedral Double-Action Manifolds: A special class of non-trivial topologies of the spherical space S^3 is
investigated with respect to their cosmic microwave background (CMB)
anisotropies. The observed correlations of the anisotropies on the CMB sky
possess on large separation angles surprising low... |
Constraining decaying dark energy density models with the CMB
temperature-redshift relation: We discuss the thermodynamic and dynamical properties of a variable dark
energy model with density scaling as $\rho_x \propto (1+z)^{m}$, z being the
redshift. These models lead to the creation/disruption of matter and radiat... | Large numbers in the Universe and the origin of the Cosmic magnetic
field: The origin of the cosmic magnetic fields is still a mystery. We use current
knowledge of galaxy formation and evolution to estimate that a charge imbalance
of $1$ every $\sim10^{39}$ in protogalaxies would solve this problem. This
imbalance co... |
The Early Dark Sector, the Hubble Tension, and the Swampland: We consider the interplay of the Early Dark Energy (EDE) model, the Swampland
Distance Conjecture (SDC), and cosmological parameter tensions. EDE is a
proposed resolution of the Hubble tension relying upon a near-Planckian scalar
field excursion, while the S... | Bulges and discs of spiral galaxies: edge-on perspective: We present a sample of edge-on spiral galaxies both of early and late
types.The sample consists of 175 galaxies in the Ks-filter, 169 galaxies in the
H-filter and 165 galaxies in the J-filter. Bulge and disc decompositions of
each galaxy image, taken from the Tw... |
The Herschel Virgo Cluster Survey XIV: transition-type dwarf galaxies in
the Virgo cluster: We use dust scaling relations to investigate the hypothesis that Virgo
cluster transition-type dwarfs are infalling star-forming field galaxies, which
is argued based on their optical features (e.g. disks, spiral arms, bars) a... | Solution to Big-Bang Nucleosynthesis in Hybrid Axion Dark Matter Model: Following a recent suggestion of axion cooling of photons between the
nucleosynthesis and recombination epochs in the Early Universe, we investigate
a hybrid model with both axions and relic supersymmetric particles. In this
model we demonstrate th... |
Encircling the dark: constraining dark energy via cosmic density in
spheres: The recently published analytic probability density function for the mildly
non-linear cosmic density field within spherical cells is used to build a
simple but accurate maximum likelihood estimate for the redshift evolution of
the variance ... | Statistical anisotropy of CMB as a probe of conformal rolling scenario: Search for the statistical anisotropy in the CMB data is a powerful tool for
constraining models of the early Universe. In this paper we focus on the
recently proposed cosmological scenario with conformal rolling. We consider two
sub-scenarios, one... |
The HiZELS/UKIRT large area survey for bright Lyman-alpha emitters at
z~9: We present the largest area survey to date (1.4 deg2) for Lyman-alpha
emitters (LAEs) at z~9, as part of the Hi-z Emission Line Survey (HiZELS). The
survey, which primarily targets H-alpha emitters at z < 3, uses the Wide Field
CAMera on the U... | Cosmological perturbations without the Boltzmann hierarchy: Calculations of the evolution of cosmological perturbations generally involve
solution of a large number of coupled differential equations to describe the
evolution of the multipole moments of the distribution of photon intensities
and polarization. However, t... |
Cosmic chronometers constraints on some fast-varying dark energy
equations of state: We consider three `four-parameters' dark energy equations of state allowing
fast transition from the matter dominated decelerating phase to the current
accelerating phase. The fast-varying nature of the dark energy models is
quantifi... | Origin of the anti-hierarchical growth of black holes: Observational studies have revealed a "downsizing" trend in black hole (BH)
growth: the number densities of luminous AGN peak at higher redshifts than
those of faint AGN. This would seem to imply that massive black holes formed
before low mass black holes, in appar... |
The Dipole of the Pantheon+SH0ES Data: In this paper we determine the dipole in the distance redshift relation from
the Pantheon+ data. We find that, while its amplitude roughly agrees with the
dipole found in the cosmic microwave background which is attributed to the
motion of the solar system with respect to the cosm... | The Phoenix Project: the Dark Side of Rich Galaxy Clusters: [abridged] We introduce the Phoenix Project, a set of $\Lambda$CDM
simulations of the dark matter component of nine rich galaxy clusters. Each
cluster is simulated at least at two different numerical resolutions. For eight
of them, the highest resolution corre... |
Testing Parity Symmetry with the Polarized Cosmic Microwave Background: New physics in the early Universe could lead to parity-violation in the late
Universe, sourcing statistics whose sign changes under point reflection. The
best constraints on such phenomena have come from the Planck temperature
fluctuations; however... | RadioAstron Early Science Program Space-VLBI AGN survey: strategy and
first results: RadioAstron is a project to use the 10m antenna on board the dedicated
SPEKTR-R spacecraft, launched on 2011 July 18, to perform Very Long Baseline
Interferometry from space - Space-VLBI. We describe the strategy and highlight
the fi... |
Galaxy orientation with the cosmic web across cosmic time: This work investigates the alignment of galactic spins with the cosmic web
across cosmic time using the cosmological hydrodynamical simulation
Horizon-AGN. The cosmic web structure is extracted via the persistent skeleton
as implemented in the DISPERSE algorith... | Consistency of cosmic microwave background temperature measurements in
three frequency bands in the 2500-square-degree SPT-SZ survey: We present an internal consistency test of South Pole Telescope (SPT)
measurements of the cosmic microwave background (CMB) temperature anisotropy
using three-band data from the SPT-SZ... |
Distinguishing interacting dark energy from wCDM with CMB, lensing, and
baryon acoustic oscillation data: We employ the Planck 2013 CMB temperature anisotropy and lensing data, and
baryon acoustic oscillation (BAO) data to constrain a phenomenological $w$CDM
model, where dark matter and dark energy interact. We assum... | SDWFS-MT-1: A Self-Obscured Luminous Supernova at z~0.2: We report the discovery of a six-month-long mid-infrared transient,
SDWFS-MT-1 (aka SN 2007va), in the Spitzer Deep, Wide-Field Survey of the NOAO
Deep Wide-Field Survey Bootes field. The transient, located in a z=0.19 low
luminosity (M_[4.5]~-18.6 mag, L/L_Milky... |
Cross-correlation of galaxies and galaxy clusters in the Sloan Digital
Sky Survey and the importance of non-Poissonian shot noise: We present measurements of angular cross power spectra between galaxies and
optically-selected galaxy clusters in the final photometric sample of the Sloan
Digital Sky Survey (SDSS). We m... | High Redshift Long Gamma-Ray Bursts Hubble Diagram as a Test of Basic
Cosmological Relations: We examine the prospects of the high redshift Long Gamma Ray Bursts (LGRB)
Hubble Diagram as a test of the basic cosmological principles. Analysis of the
Hubble Diagram allows us to test several fundamental cosmological prin... |
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