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A Measurement of the Cosmic Microwave Background Damping Tail from the 2500-square-degree SPT-SZ survey: We present a measurement of the cosmic microwave background (CMB) temperature power spectrum using data from the recently completed South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) survey. This measurement is made...
Epoch of reionization parameter estimation with the 21-cm bispectrum: We present the first application of the isosceles bispectrum to MCMC parameter inference from the cosmic 21-cm signal. We extend the MCMC sampler 21cmMC to use the fast bispectrum code, BiFFT, when computing the likelihood. We create mock 1000h obser...
The Spitzer/IRAC view of black hole - bulge scaling relations: We present a mid-IR investigation of the scaling relations between supermassive black hole masses (MBH) and the structural parameters of the host spheroids in local galaxies. The work is based on two-dimensional bulge-disk decompositions of Spitzer/IRAC 3.6...
Reheating in 3-form inflation: We consider the 3-form field, which has been considered as a candidate for realizing inflation, coupled to a scalar field which models the relativistic matter particles produced during the reheating epoch. We have investigated the stability conditions for this theory and found that introd...
Interplay of CMB Temperature, Space Curvature, and Expansion Rate Parameters: The cosmic microwave background (CMB) temperature, $T$, surely the most precisely measured cosmological parameter, has been inferred from {\it local} measurements of the blackbody spectrum to an exquisite precision of 1 part in $\sim 4700$....
Combining cluster number counts and galaxy clustering: The abundance of clusters and the clustering of galaxies are two of the important cosmological probes for current and future large scale surveys of galaxies, such as the Dark Energy Survey. In order to combine them one has to account for the fact that they are not ...
Backreaction in late-time cosmology: We review the effect of the formation of nonlinear structures on the expansion rate, spatial curvature and light propagation in the universe, focusing on the possibility that it could explain cosmological observations without the introduction of dark energy or modified gravity. We c...
Mass bias and cosmological constraints from Planck cluster clustering: We analysed the 3D clustering of the Planck sample of Sunyaev-Zeldovich (SZ) selected galaxy clusters, focusing on the redshift-space two-point correlation function (2PCF). We compared our measurements to theoretical predictions of the standard $\La...
RAY-RAMSES: a code for ray tracing on the fly in N-body simulations: We present a ray tracing code to compute integrated cosmological observables on the fly in AMR N-body simulations. Unlike conventional ray tracing techniques, our code takes full advantage of the time and spatial resolution attained by the N-body simu...
Accurate calculations of the WIMP halo around the Sun and prospects for gamma ray detection: Weakly interacting massive particles (WIMPs) can be captured by heavenly objects, like the Sun. Under the process of being captured by the Sun, they will build up a population of WIMPs around it, that will eventually sink to ...
Updating the MACHO fraction of the Milky Way dark halo with improved mass models: Recent interest in primordial black holes as a possible dark matter candidate has motivated the reanalysis of previous methods for constraining massive astrophysical compact objects in the Milky Way halo and beyond. In order to derive t...
Testing DARKexp against energy and density distributions of Millennium-II halos: We test the DARKexp model for relaxed, self-gravitating, collisionless systems against equilibrium dark matter halos from the Millennium-II simulation. While limited tests of DARKexp against simulations and observations have been carried...
Optical Ring Cavity Search for Axion Dark Matter: We propose a novel experiment to search for axion dark matter which differentiates the phase velocities of the left and right-handed polarized photons. Our optical cavity measures the difference of the resonant frequencies between two circular-polarizations of the laser...
Transients from initial conditions based on Lagrangian perturbation theory in $N$-body simulations II: the effect of the transverse mode: We study the initial conditions for cosmological $N$-body simulations for precision cosmology. In general, Zel'dovich approximation has been applied for the initial conditions of $...
Cosmic Recombination in the Presence of Primordial Magnetic Fields: Primordial magnetic fields (PMFs) may explain observations of magnetic fields on extragalactic scales. They are most cleanly constrained by observations of details of the cosmic microwave background radiation (CMB) Their effects on cosmic recombination...
Parity-odd correlators of diffuse gamma rays and intergalactic magnetic fields: We develop the connection between intergalactic helical magnetic fields and parity odd signatures in the diffuse gamma ray sky. We find that the location and the amplitude of a peak in a parity odd correlator, $Q(R)$, can be used to infer...
What X-ray source counts can tell about large-scale matter distribution: Sources generating most of the X-ray background (XRB) are dispersed over a wide range of redshifts. Thus, statistical characteristics of the source distribution carry information on matter distribution on very large scales. We test the possibility...
Radio galaxy feedback in X-ray selected groups from COSMOS: the effect on the ICM: We quantify the importance of the mechanical energy released by radio-galaxies inside galaxy groups. We use scaling relations to estimate the mechanical energy released by 16 radio-AGN located inside X-ray detected galaxy groups in the...
Radio and X-ray properties of submillimeter galaxies in the A2125 field: We present the radio and X-ray properties of 1.2 mm MAMBO source candidates in a 1600 sq. arcmin field centered on the Abell 2125 galaxy cluster at z=0.247. The brightest, non-synchrotron mm source candidate in the field has a photometric redshift...
A Standard Ruler at Cosmic Dawn: The matter in our Universe comes in two flavors: dark and baryonic. Of these, only the latter couples to photons, giving rise to the well-known baryon acoustic oscillations and, in the process, generating supersonic relative velocities between dark matter and baryons. These velocities--...
The Emission Line Properties of Gravitationally-lensed 1.5 < z < 5 Galaxies: We present and analyse near-infrared spectroscopy for a sample of 28 gravitationally- lensed star-forming galaxies in the redshift range 1.5 < z < 5, observed mostly with the Keck II telescope. With typical magnifications of ~1.5-4 magnitude...
A black box for dark sector physics: Predicting dark matter annihilation feedback with conditional GANs: Traditionally, incorporating additional physics into existing cosmological simulations requires re-running the cosmological simulation code, which can be computationally expensive. We show that conditional Generat...
A Detailed Study of the Lobes of Eleven Powerful Radio Galaxies: Radio lobes of a sample of eleven very powerful classical double radio galaxies were studied. Each source was rotated so that the symmetry axis of the source was horizontal, and vertical cross-sectional cuts were taken across the source at intervals of on...
Energetic constraints to chemo-photometric evolution of spiral galaxies: The problem of chemo-photometric evolution of late-type galaxies is dealt with relying on prime physical arguments of energetic self-consistency between chemical enhancement of galaxy mass, through nuclear processing inside stars, and luminosity e...
Artificial Neural Network Spectral Light Curve Template for Type Ia Supernovae and its Cosmological Constraints: The spectral energy distribution (SED) sequence for type Ia supernovae (SN Ia) is modeled by an artificial neural network. The SN Ia luminosity is characterized as a function of phase, wavelength, a color ...
Long Term Monitoring of the Dynamics and Particle Acceleration of Knots in the Jet of Centaurus A: We present new and archival multi-frequency radio and X-ray data for Centaurus A obtained over almost 20 years at the VLA and with Chandra, with which we measure the X-ray and radio spectral indices of jet knots, flux d...
Instabilities in neutrino systems induced by interactions with scalars: If there are scalar particles of small or moderate mass coupled very weakly to Dirac neutrinos, in a minimal way, then neutrino-anti-neutrino clouds of sufficient number density can experience an instability in which helicities are suddenly reverse...
SDSS J094604.90+183541.8: A Gravitationally Lensed Quasar at z=4.8: We report the discovery of a gravitationally lensed quasar identified serendipitously in the Sloan Digital Sky Survey (SDSS). The object, SDSS J094604.90+183541.8, was initially targeted for spectroscopy as a luminous red galaxy, but the SDSS spectrum ...
Dependences of Type Ia Supernovae Lightcurve Parameters on the Host Galaxy Star Formation Rate and Metallicity: We present the dependences of the properties of type Ia Supernovae (SNe Ia) on their host galaxies by analyzing the multi-band lightcurves of 118 spectroscopically confirmed SNe Ia observed by the Sloan Dig...
The Carnegie Hubble Program: The Infrared Leavitt Law in IC 1613: We have observed the dwarf galaxy IC 1613, at multiple epochs in the mid--infrared using Spitzer and contemporaneously in the near--infrared using the new FourStar near-IR camera on Magellan. We have constructed Cepheid period--luminosity relations in th...
Is a symmetric matter-antimatter universe excluded?: We consider a non-standard cosmological model in which the universe contains as much matter as antimatter on large scales and presents a local baryon asymmetry. A key ingredient in our approach is that the baryon density distribution follows Gaussian fluctuations aro...
Cosmological structure formation in complex scalar field dark matter versus real ultralight axions: a comparative study using CLASS: (abridged) We continue the study of $\Lambda$SFDM cosmologies, which differ from $\Lambda$CDM in that CDM is replaced by scalar field dark matter (SFDM) by calculating the evolution of ...
Minor merger-induced cold fronts in Abell 2142 and RXJ1720.1+2638: We present evidence for the existence of substructure in the "relaxed appearing" cold front clusters Abell 2142 and RXJ1720.1+2638. The detection of these substructures was made possible by comprehensive multi-object optical spectroscopy obtained with t...
Can primordial parity violation explain the observed cosmic birefringence?: Recently, the cross-correlation between $E$- and $B$-mode polarization of the cosmic microwave background (CMB), which is well explained by cosmic birefringence with rotation angle $\beta\approx 0.3$ deg, has been found in CMB polarization da...
Consistency Relation and Non-Gaussianity in a Galileon Inflation: We study a particular Galileon inflation in the light of Planck2015 observational data in order to constraint the model parameter space. We study the spectrum of the primordial modes of the density perturbations by expanding the action up to the second o...
Effect of Population III Multiplicity on Dark Star Formation: We numerically study the mutual interaction between dark matter (DM) and Population III (Pop III) stellar systems in order to explore the possibility of Pop III dark stars within this physical scenario. We perform a cosmological simulation, initialized at z ...
The Chemical Evolution of Narrow Emission Line Galaxies: the Key to their Formation Processes: Using the largest sample of narrow emission line galaxies available so far, we show that their spectral characteristics are correlated with different physical parameters, like the chemical abundances, the morphologies, the ...
Scalar instabilities in bimetric gravity: The Vainshtein mechanism and structure formation: We investigate the observational consequences of scalar instabilities in bimetric theory, under the assumption that the Vainshtein mechanism restores general relativity within a certain distance from gravitational sources. We ...
A new way to test the Cosmological Principle: measuring our peculiar velocity and the large scale anisotropy independently: We present a novel approach to disentangle two key contributions to the largest-scale anisotropy of the galaxy distribution: (i) the intrinsic dipole due to clustering and anisotropic geometry, ...
Cosmological simulations of the same spiral galaxy: connecting the dark matter distribution of the host halo with the subgrid baryonic physics: The role of baryonic physics, star formation, and stellar feedback, in shaping the galaxies and their host halos is an evolving topic. The dark matter aspects are illustrated...
Baryon Acoustic Oscillations reconstruction with pixels: Gravitational non-linear evolution induces a shift in the position of the baryon acoustic oscillations (BAO) peak together with a damping and broadening of its shape that bias and degrades the accuracy with which the position of the peak can be determined. BAO re...
The possible resolution of Boltzmann brains problem in phantom cosmology: We consider the well-known Boltzmann brains problem in frames of simple phantom energy models with little rip and big rip singularity. It is showed that these models (i) satisfy to observational data and (ii) may be free from Boltzmann brains pro...
Combining Full-Shape and BAO Analyses of Galaxy Power Spectra: A 1.6% CMB-independent constraint on H0: We present cosmological constraints from a joint analysis of the pre- and post-reconstruction galaxy power spectrum multipoles from the final data release of the Baryon Oscillation Spectroscopic Survey (BOSS). Geom...
Cosmological evolution of Witten superconducting string networks: We consider the evolution of current-carrying cosmic string networks described by the charge-velocity-dependent one scale (CVOS) model beyond the linear equation of state regime, specifically focusing on the Witten superconducting model. We find that, ge...
Molecular Gas Evolution across a Spiral Arm in M 51: We present sensitive and high angular resolution CO(1-0) data obtained by the Combined Array for Research in Millimeter-wave Astronomy (CARMA) observations toward the nearby grand-design spiral galaxy M 51. The angular resolution of 0.7" corresponds to 30 pc, which i...
GW190425, GW190521 and GW190814: Three candidate mergers of primordial black holes from the QCD epoch: The two recent gravitational-wave events GW190425 and GW190814 from the third observing run of LIGO/Virgo have both a companion which is unexpected if originated from a neutron star or a stellar black hole, with mas...
Stellar population and kinematics of NGC404: NGC404 is a nearly face-on nearby low-luminosity lenticular galaxy. Probing its characteristics provides a wealth of information on the details of possible evolution processes of dS0 galaxies which may not be possible in other, more distant objects. In order to study its kin...
New constraints on the distance duality relation from the local data: The cosmic distance duality relation (DDR), which connects the angular diameter distance and luminosity distance through a simple formula $D_A(z)(1+z)^2/D_L(z)\equiv1$, is an important relation in cosmology. Therefore, testing the validity of DDR is ...
3D-structure of the Canes Venatici I Cloud: We present the improved distance moduli of 30 galaxies in the Canes Venatici I Cloud using advanced Tip of Red Giant Branch (TRGB) method (Makarov et.al. 2006). The method was determined for accurate estimation of the distances even if TRGB situated near photometric limit. Th...
Comment on cluster analysis of radio loops in CMB data: A recent article (Liu et al. 2014) looks for evidence in the WMAP internal linear combination map (ILC) of unmodeled emission from the galactic radio loop known as Loop I. The statistically strongest result comes from a cluster analysis that tests whether the "hot...
The largest structure of the Universe, defined by Gamma-Ray Bursts: Research over the past three decades has revolutionized the field of cosmology while supporting the standard cosmological model. However, the cosmological principle of Universal homogeneity and isotropy has always been in question, since structures as ...
The dominant role of mergers in the size evolution of massive early-type galaxies since z ~ 1: In this paper we measure the merger fraction and rate, both minor and major, of massive early-type galaxies (M_star >= 10^11 M_Sun) in the COSMOS field, and study their role in mass and size evolution. We use the 30-band ph...
CMB Polarization Systematics, Cosmological Birefringence and the Gravitational Waves Background: Cosmic Microwave Background experiments must achieve very accurate calibration of their polarization reference frame to avoid biasing the cosmological parameters. In particular, a wrong or inaccurate calibration might mim...
Tests of Chameleon Gravity: Theories of modified gravity where light scalars with non-trivial self-interactions and non-minimal couplings to matter-chameleon and symmetron theories-dynamically suppress deviations from general relativity in the solar system. On other scales, the environmental nature of the screening mea...
The Djorgovski-Gurzadyan dark energy integral equation and the Hubble diagram: We consider the observational aspects of the value of dark energy density from quantum vacuum fluctuations based initially on the Gurzadyan-Xue model. We reduce the Djorgovski-Gurzadyan integral equation to a differential equation for the ...
The Aemulus Project I: Numerical Simulations for Precision Cosmology: The rapidly growing statistical precision of galaxy surveys has lead to a need for ever-more precise predictions of the observables used to constrain cosmological and galaxy formation models. The primary avenue through which such predictions will be ...
The impact and response of minihalos and the inter-halo medium on cosmic reionization: An ionization front (I-front) that propagates through an inhomogeneous medium is slowed down by self-shielding and recombinations. We perform cosmological radiation hydrodynamics simulations of the I-front propagation during the ep...
Heating the IGM by X-rays from Population III Binaries in High Redshift Galaxies: Due to their long mean free path, X-rays are expected to have an important impact on cosmic reionization by heating and ionizing the IGM on large scales, especially after simulations have suggested that Population III stars may form in ...
A new recipe for $Λ$CDM: It is well known that a canonical scalar field is able to describe either dark matter or dark energy but not both. We demonstrate that a non-canonical scalar field can describe both dark matter and dark energy within a unified setting. We consider the simplest extension of the canonical Lagrang...
Bayesian analysis for a class of $α$-attractor inflationary models: We perform a Bayesian study of a generalization of the basic $\alpha$-attractor T model given by the potential $V(\phi)=V_0\left[1-\text{sech}^{p}\left(\phi/\sqrt{6\alpha}M_{pl}\right)\right]$ where $\phi$ is the inflaton field and the parameter $\alph...
Anisotropic dark energy and ellipsoidal universe: A cosmological model with anisotropic dark energy is analyzed. The amount of deviation from isotropy of the equation of state of dark energy, the skewness \delta, generates an anisotropization of the large-scale geometry of the Universe, quantifiable by means of the act...
Signs of Interacting Vacuum and Dark Matter in the Universe: We consider the impact of dynamical dark energy (DDE) in the possible solution of the existing tensions in the $\Lambda$CDM. We test both interacting and non-interacting DE models with dark matter (DM). Among the former, the running vacuum model (RVM) interac...
Describing variations of the Fisher-matrix across parameter space: Forecasts in cosmology, both with Monte-Carlo Markov-chain methods and with the Fisher matrix formalism, depend on the choice of the fiducial model because both the signal strength of any observable as well as the model nonlinearities linking observable...
Lensing smoothing of BAO wiggles: We study non-perturbatively the effect of the deflection angle on the BAO wiggles of the matter power spectrum in real space. We show that from redshift z~2 this introduces a dispersion of roughly 1 Mpc at BAO scale, which corresponds approximately to a 1% effect. The lensing effect in...
First CMB Constraints on Direction-Dependent Cosmological Birefringence from WMAP-7: A Chern-Simons coupling of a new scalar field to electromagnetism may give rise to cosmological birefringence, a rotation of the linear polarization of electromagnetic waves as they propagate over cosmological distances. Prior work h...
Constraints on neutrino mass from Cosmic Microwave Background and Large Scale Structure: Our tightest upper limit on the sum of neutrino mass eigenvalues $M_\nu$ comes from cosmological observations that will improve substantially in the near future, enabling a detection. The combination of the Baryon Acoustic Oscill...
Searching for dark matter annihilation from individual halos: uncertainties, scatter and signal-to-noise ratios: Individual extragalactic dark matter halos, such as those associated with nearby galaxies and galaxy clusters, are promising targets for searches for gamma-rays from dark matter annihilation. We review the...
Bispectrum Supersample Covariance: Modes with wavelengths larger than the survey window can have significant impact on the covariance within the survey window. The supersample covariance has been recognized as an important source of covariance for the power spectrum on small scales, and it can potentially be important ...
Mass Function Predictions Beyond LCDM: The mass distribution of halos, as specified by the halo mass function, is a key input for several cosmological probes. The sizes of $N$-body simulations are now such that, for the most part, results need no longer be statistics-limited, but are still subject to various systematic...
Results from EDGES High-Band: III. New Constraints on Parameters of the Early Universe: We present new constraints on parameters of cosmic dawn and the epoch of reionization derived from the EDGES High-Band spectrum ($90-190$ MHz). The parameters are probed by evaluating global $21$ cm signals generated with the rece...
Lepton Flavour Asymmetries and the Mass Spectrum of Primordial Black Holes: We study the influence of lepton flavour asymmetries on the formation and the mass spectrum of primordial black holes. We estimate the detectability of their mergers with LIGO/Virgo and show that the currently published gravitational wave eve...
Direct Detections of Young Stars in Nearby Elliptical Galaxies: Small amounts of star formation in elliptical galaxies are suggested by several results: surprisingly young ages from optical line indices, cooling X-ray gas, and mid-IR dust emission. Such star formation has previously been difficult to directly detect, b...
IDCS J1426.5+3508: Sunyaev-Zel'dovich Measurement of a Massive IR-selected Cluster at z=1.75: We report 31 GHz CARMA observations of IDCS J1426.5+3508, an infrared-selected galaxy cluster at z = 1.75. A Sunyaev-Zel'dovich decrement is detected towards this cluster, indicating a total mass of M200 = (4.3 +/- 1.1) x 10...
Principal Components of CMB non-Gaussianity: The skew-spectrum statistic introduced by Munshi & Heavens (2010) has recently been used in studies of non-Gaussianity from diverse cosmological data sets including the detection of primary and secondary non-Gaussianity of Cosmic Microwave Background (CMB) radiation. Extendi...
Future constraints on the gravitational slip with the mass profiles of galaxy clusters: The gravitational slip parameter is an important discriminator between large classes of gravity theories at cosmological and astrophysical scales. In this work we use a combination of simulated information of galaxy cluster mass p...
Influence of the Environment on PAH Emission in Star-Forming Regions: We investigate the emission properties of polycyclic aromatic hydrocarbons (PAHs) in various metallicity environments with the Infrared Spectrograph on board Spitzer. Local giant HII regions are used as references as they enable access to the distinc...
Neutral Hydrogen Tully Fisher Relation: The case for Newtonian Gravity: Intrinsic luminosities are related to rotation velocities of disk galaxies by Tully Fisher (TF) relations. The Baryonic TF (BTF) relation has recently been explained with Dark Matter and Newtonian Gravity as well as Modified Newtonian Dynamics (MON...
Implications of hydrodynamical simulations for the interpretation of direct dark matter searches: In recent years, realistic hydrodynamical simulations of galaxies like the Milky Way have become available, enabling a reliable estimate of the dark matter density and velocity distribution in the Solar neighborhood. We ...
Gravitational waves from cosmological phase transitions: I discuss the generation of a stochastic background of gravitational waves during a first order phase transition. I present simple general arguments which explain the main features of the gravitational wave spectrum like the $k^3$ power law growth on large scales...
Planck Early Results XXVI: Detection with Planck and confirmation by XMM-Newton of PLCK G266.6-27.3, an exceptionally X-ray luminous and massive galaxy cluster at z~1: We present first results on PLCK G266.6-27.3, a galaxy cluster candidate detected at a signal-to-noise ratio of 5 in the Planck All Sky survey. An X...
Cosmic Magnetic Fields: from Stars and Galaxies to the Primordial Universe: Most of the baryonic matter in the Universe is permeated by magnetic fields which affect many, if not most, of astrophysical phenomena both, in compact sources and in diffuse gas. Recent years have been marked by a worldwide surge of interest...
Microwave and radio emission of dusty star-forming galaxies: Implication for the cosmic radio background: We use the most up-to-date cosmological evolution models of star-forming (SF) galaxies and radio sources to compute the extragalactic number counts and the cosmic background from 408MHz to 12THz. The model of SF ...
The Influence of AGN Feedback on Galaxy Cluster Observables: Galaxy clusters are valuable cosmological probes. However, cluster mass estimates rely on observable quantities that are affected by complicated baryonic physics in the intracluster medium (ICM), including feedback from active galactic nuclei (AGN). Cosmologi...
Extracting key information from spectroscopic galaxy surveys: We develop a novel method to extract key cosmological information, which is primarily carried by the baryon acoustic oscillations and redshift space distortions, from spectroscopic galaxy surveys based on a joint principal component analysis (PCA) and massiv...
Metallicity effects in the spectral classification of O-type stars. Theoretical consideration: Based on an exteded grid of NLTE, line blanketed model atmospheres with stellar winds as calculated by means of FASTWIND, we have investigated the change in the strengths of strategic Helium transitions in the optical as ca...
Prospects for Delensing the Cosmic Microwave Background for Studying Inflation: A detection of excess cosmic microwave background (CMB) B-mode polarization on large scales allows the possibility of measuring not only the amplitude of these fluctuations but also their scale dependence, which can be parametrized as the...
Photometric Redshifts for Next-Generation Surveys: Photometric redshifts are essential in studies of both galaxy evolution and cosmology, as they enable analyses of objects too numerous or faint for spectroscopy. The Rubin Observatory, Euclid, and Roman Space Telescope will soon provide a new generation of imaging surv...
SZ Scaling Relations of Galaxy Groups and Clusters Near the North Ecliptic Pole: SZ scaling relations have been used to test the self-similar prediction for massive galaxy clusters, but little attention has been given to individual galaxy groups. We investigate the scaling relations of galaxy groups and clusters near...
A Groundbased Imaging Study of Galaxies Causing DLA, subDLA, and LLS Absorption in Quasar Spectra: We present results from a search for galaxies that give rise to damped Lyman alpha (DLA), subDLA, and Lyman limit system (LLS) absorption at redshifts 0.1 ~< z ~< 1 in the spectra of background quasars. The sample was f...
Testing the Cosmic Anisotropy with Supernovae Data: Hemisphere Comparison and Dipole Fitting: The cosmological principle is one of the cornerstones in modern cosmology. It assumes that the universe is homogeneous and isotropic on cosmic scales. Both the homogeneity and the isotropy of the universe should be tested ca...
The invariant Twist of Magnetic Fields in the Relativistic Jets of Active Galactic Nuclei: The origin of cosmic magnetic (B) fields remains an open question. It is generally believed that very weak primordial B fields are amplified by dynamo processes, but it appears unlikely that the amplification proceeds fast enou...
Mass and magnification maps for the Hubble Space Telescope Frontier Fields clusters: implications for high redshift studies: Extending over three Hubble Space Telescope (HST) cycles, the Hubble Frontier Fields (HFF) initiative constitutes the largest commitment ever of HST time to the exploration of the distant Unive...
Thermal Friction as a Solution to the Hubble and Large-Scale Structure Tensions: Thermal friction offers a promising solution to the Hubble and the large-scale structure (LSS) tensions. This additional friction acts on a scalar field in the early universe and extracts its energy density into dark radiation, the cumul...
Rhapsody-G simulations I: the cool cores, hot gas and stellar content of massive galaxy clusters: We present the Rhapsody-G suite of cosmological hydrodynamic AMR zoom simulations of ten massive galaxy clusters at the $M_{\rm vir}\sim10^{15}\,{\rm M}_\odot$ scale. These simulations include cooling and sub-resolution ...
TeV blazars and their distance: Recently, a new method to constrain the distance of blazars with unknown redshift using combined observations in the GeV and TeV regimes has been developed, with the underlying assumption that the Very High Energy (VHE) spectrum corrected for the absorption of TeV photons by the Extragal...
Galaxy Alignments in Very X-ray Luminous Clusters at z>0.5: We present the results of a search for galaxy alignments in 12 galaxy clusters at z>0.5, a statistically complete subset of the very X-ray luminous clusters from the MAssive Cluster Survey (MACS). Using high-quality images taken with the Hubble Space Telescope...
Detection of a Companion Lens Galaxy using the Mid-infrared Flux Ratios of the Gravitationally Lensed Quasar H1413+117: We present the first resolved mid-IR (11 micron) observations of the four-image quasar lens H1413+117 using the Michelle camera on Gemini North. All previous observations (optical, near-IR, and radi...
Assembly Bias & Redshift-Space Distortions: Impact on cluster dynamics tests of general relativity: The redshift-space distortion (RSD) of galaxies surrounding massive clusters is emerging as a promising testbed for theories of modified gravity. Conventional applications of this method rely upon the assumption that t...
Imprints of decaying dark matter on cosmic voids: The Standard Cosmological Model assumes that more than 85\% of matter is in the form of collisionless and pressureless dark matter. Unstable decaying dark matter has been proposed in the literature as an extension to the standard cold dark matter model. In this paper we...
The influence of mergers on the cluster temperature function and cosmological parameters derived from it: We develop a parameter-free analytic model to include the effects of mergers into the theoretical modelling of the X-ray temperature function of galaxy clusters. We include this description into our model for the...
Gravothermal Catastrophe with a Cosmological Constant: We investigate the effect of a cosmological constant on the gravothermal catastrophe in the Newtonian limit. A negative cosmological constant acts as a thermodynamic `destabilizer'. The Antonov radius gets smaller and the instability occurs, not only for negative b...
A jet-driven dynamo (JEDD) from jets-inflated bubbles in cooling flows: I suggest that the main process that amplifies magnetic fields in cooling flows in clusters and group of galaxies is a jet-driven dynamo (JEDD). The main processes that are behind the JEDD is the turbulence that is formed by the many vortices forme...
The Cosmological Parameters (2019): This is a review article for The Review of Particle Physics 2020 (aka the Particle Data Book). It forms a compact review of knowledge of the cosmological parameters at the end of 2019. Topics included are Parametrizing the Universe; Extensions to the standard model; Probes; Bringing ...
Galaxy and Mass Assembly (GAMA): Colour and luminosity dependent clustering from calibrated photometric redshifts: We measure the two-point angular correlation function of a sample of 4,289,223 galaxies with r < 19.4 mag from the Sloan Digital Sky Survey as a function of photometric redshift, absolute magnitude and c...
The Problem of Inertia in Friedmann Universes: In this paper we study the origin of inertia in a curved spacetime, particularly the spatially flat, open and closed Friedmann universes. This is done using Sciama's law of inertial induction, which is based on Mach's principle, and expresses the analogy between the retard...
Warm dark matter does not do better than cold dark matter in solving small-scale inconsistencies: Over the last decade, warm dark matter (WDM) has been repeatedly proposed as an alternative scenario to the standard cold dark matter (CDM) one, potentially resolving several disagreements between the CDM model and obser...
The Layzer-Irvine Equation for Scalar-Tensor Theories: A Test of Modified Gravity N-body Simulations: The Layzer-Irvine equation describes energy conservation for a pressure less fluid interacting though quasi-Newtonian gravity in an expanding Universe. We here derive a Layzer-Irvine equation for scalar field theorie...
CMB EB and TB cross-spectrum estimation via pseudo-spectrum techniques: We discuss methods for estimating EB and TB spectra of the Cosmic Microwave Background anisotropy maps covering limited sky area. Such odd-parity correlations are expected to vanish whenever parity is not broken. As this is indeed the case in the s...
Gravitational Heating Helps Make Massive Galaxies Red and Dead: We study the thermal formation history of four simulated galaxies that were shown in Naab et al. (2007) to reproduce a number of observed properties of elliptical galaxies. The temperature of the gas in the galaxies is steadily increasing with decreasing r...
Lifting the Veil of Dust from NGC 0959: The Importance of a Pixel-Based 2D Extinction Correction: We present the results of a study of the late-type spiral galaxy NGC 0959, before and after application of the pixel-based dust extinction correction described in Tamura et al. 2009 (Paper I). Galaxy Evolution Explorer (...
Parity in Planck full-mission CMB temperature maps: In the standard model of cosmology, Cosmic Microwave Background (CMB) sky is expected to show no symmetry preferences. Following our previous studies, we explore the presence of any particular parity preference in the latest full-mission CMB temperature maps from ESA'...
Debiasing Standard Siren Inference of the Hubble Constant with Marginal Neural Ratio Estimation: Gravitational wave (GW) standard sirens may resolve the Hubble tension, provided that standard siren inference of $H_0$ is free from systematic biases. However, standard sirens from binary neutron star (BNS) mergers suffe...
The X-ray to optical-UV luminosity ratio of X-ray selected Type 1 AGN in XMM-COSMOS: We present a study of the X-ray to optical properties of a sample of 545 X-ray selected Type 1 AGN, from the XMM-COSMOS survey, over a wide range of redshifts ($0.04<\z<4.25$) and X-ray luminosities ($40.6 \leq \Log \Lhard \leq 45.3$...
Dry minor mergers and size evolution of high-z compact massive early-type galaxies: Recent observations show evidence that high-z (z\sim 2 - 3) early-type galaxies (ETGs) are more compact than those with comparable mass at z\sim 0. Such a size evolution is most likely explained by the `Dry Merger Sceanario'. However,...
Scaling relations of the slightly self-interacting cold dark matter in galaxies and clusters: Recent observations in galaxies and clusters indicate dark matter density profiles exhibit core-like structures which contradict to the numerical simulation results of collisionless cold dark matter. The idea of self-interac...
Unfolding the matter distribution using 3-D weak gravitational lensing: Combining redshift and galaxy shape information offers new exciting ways of exploiting the gravitational lensing effect for studying the large scales of the cosmos. One application is the three-dimensional reconstruction of the matter density distr...
The Redshift and Mass Dependence on the Formation of The Hubble Sequence at z>1 from CANDELS/UDS: In this paper we present a detailed study of the structures and morphologies of a sample of 1188 massive galaxies with Mstar>10^10Msun between redshifts z=1-3 within the Ultra Deep Survey (UDS) region of the Cosmic Assem...
Non-Linearity-Free prediction of the growth-rate $fσ_8$ using Convolutional Neural Networks: The growth-rate $f\sigma_8(z)$ of the large-scale structure of the Universe is an important dynamic probe of gravity that can be used to test for deviations from General Relativity. However, in order for galaxy surveys to ext...
Breaking of self-averaging properties and selection effects in the Luminous Red Galaxies sample: We study the statistical properties of the Luminous Red Galaxies sample from the Sloan Digital Sky Survey. In particular we test, by determining the probability density function (PDF) of galaxy (conditional) counts in sph...
Physical Properties, Star Formation, and Active Galactic Nucleus Activity in Balmer Break Galaxies at 0 < z < 1: We present a spectroscopic study with the derivation of the physical properties of 37 Balmer break galaxies, which have the necessary lines to locate them in star-forming-AGN diagnostic diagrams. These gal...
The abundance of Bullet-groups in LCDM: We estimate the expected distribution of displacements between the two dominant dark matter (DM) peaks (DM-DM displacements) and between DM and gaseous baryon peak (DM-gas displacements) in dark matter halos with masses larger than $10^{13}$ Msun/h. We use as a benchmark the obse...
Chemical Evolution of Dwarf Irregular and Blue Compact Galaxies: Dwarf irregular and blue compact galaxies are very interesting objects since they are relatively simple and unevolved. We present new models for the chemical evolution of these galaxies by assuming different regimes of star formation (bursting and continu...
Measuring the temperature and profiles of Lyman-$α$ absorbers: The distribution of the absorption line broadening observed in the Ly$\alpha$ forest carries information about the temperature and widths of the filaments in the intergalactic medium (IGM). In this work, we present and test a new method for inferring the te...
Do current cosmological observations rule out all Covariant Galileons?: We revisit the cosmology of Covariant Galileon gravity in view of the most recent cosmological data sets, including weak lensing. As a higher derivative theory, Covariant Galileon models do not have a $\Lambda$CDM limit and predict a very different...
A dynamical mass estimator for high z galaxies based on spectroastrometry: Galaxy dynamical masses are important physical quantities to constrain galaxy evolutionary models, especially at high redshifts. However, at z~2 the limited signal to noise ratio and spatial resolution of the data usually do not allow spatiall...
The Hidden Mass and Large Spatial Extent of a Poststarburst Galaxy Outflow: Outflowing winds of multiphase plasma have been proposed to regulate the buildup of galaxies, but key aspects of these outflows have not been probed with observations. Using ultraviolet absorption spectroscopy, we show that "warm-hot" plasma ...
Large-scale Motions in the Perseus Galaxy Cluster: By combining large-scale mosaics of ROSAT PSPC, XMM-Newton, and Suzaku X-ray observations, we present evidence for large-scale motions in the intracluster medium of the nearby, X-ray bright Perseus Cluster. These motions are suggested by several alternating and interle...
The XXL Survey. XIII. Baryon content of the bright cluster sample: Traditionally, galaxy clusters have been expected to retain all the material accreted since their formation epoch. For this reason, their matter content should be representative of the Universe as a whole, and thus their baryon fraction should be close ...
Inflaton-driven early dark energy: By arranging the control parameters, we examine whether the mass varying neutrino model PRD 103, 063540 (2021), enabling one to unify inflation with the present dark energy, can be used for producing an early dark energy. The model works in the following way. At early stages of the Bi...
Daily modulation due to channeling in direct dark matter crystalline detectors: The channeling of the ion recoiling after a collision with a WIMP in direct dark matter crystalline detectors produces a larger scintillation or ionization signal than otherwise expected. Channeling is a directional effect which depends o...
Reconstruction of cosmological matter perturbations in Modified Gravity: The analysis of perturbative quantities is a powerful tool to distinguish between different Dark Energy models and gravity theories degenerated at the background level. In this work, we generalise the integral solution of the matter density contra...
The Origins of AGN Obscuration: The 'Torus' as a Dynamical, Unstable Driver of Accretion: Multi-scale simulations have made it possible to follow gas inflows onto massive black holes (BHs) from galactic scales to the accretion disk. When sufficient gas is driven towards the BH, gravitational instabilities generically...
Small Field models with ACTPol and BICEP3 data -- Likelihood analysis: We perform a Bayesian analysis for small field models of inflation, using the most recent datasets produced by Planck`18, ACTPol, and BICEP3. We employ Artificial Neural Networks (ANN) to perform analyses with model coefficients, instead of their pr...
The impact of line-of-sight structures on measuring $H_0$ with strong lensing time-delays: Measurements of The Hubble-Lemaitre constant from early- and local-universe observations show a significant discrepancy. In an attempt to understand the origin of this mismatch, independent techniques to measure H0 are required...
Cosmology with kSZ: breaking the optical depth degeneracy with Fast Radio Bursts: The small-scale cosmic microwave background (CMB) is dominated by anisotropies from the kinematic Sunyaev-Zeldovich (kSZ) effect, and upcoming experiments will measure it very precisely, but the optical depth degeneracy limits the cosmo...
Multi-frequency measurements of the NVSS foreground sources in the Cosmic Background Imager fields. I. Data release: We present the results of the flux density measurements at 4.85 GHz and 10.45 GHz of a sample of 5998 NVSS radio sources with the Effelsberg 100 m telescope. The initial motivation was the need to iden...
Exploring Inflationary Initial State With Large Scale Structure Observations: We investigate for possible constraints on inflationary initial state from Large Scale Structure (LSS) observations. Using a model-independent framework, we build the template for the generic initial state and construct the matter power spe...
Weak lensing mass modeling bias and the impact of miscentring: Parametric modeling of galaxy cluster density profiles from weak lensing observations leads to a mass bias, whose detailed understanding is critical in deriving accurate mass-observable relations for constraining cosmological models. Drawing from existing m...
Pattern Speeds of Bars and Spiral Arms From H-alpha Velocity Fields: We have applied the Tremaine-Weinberg method to 10 late-type barred spiral galaxies using data cubes, in H-alpha emission, from the GHAFAS and FANTOMM Fabry-Perot spectrometers. We have combined the derived bar (and/or spiral) pattern speeds with angu...
Cosmological Implications of the Tetron Model of Elementary Particles: Based on a possible solution to the tetron spin problem, a modification of the standard Big Bang scenario is suggested, where the advent of a spacetime manifold is connected to the appearance of tetronic bound states. The metric tensor is constructe...
Tailoring Strong Lensing Cosmographic Observations: Strong lensing time delay cosmography has excellent complementarity with other dark energy probes, and will soon have abundant systems detected. We investigate two issues in the imaging and spectroscopic followup required to obtain the time delay distance. The first i...
Star formation and environment in clusters up to z~2.2: The dependence of galaxy star formation activity on environment - especially in clusters - at high redshift is still poorly understood, as illustrated by the still limited number of z>1.4 clusters on the one hand, and by the still debated star formation-density re...
Major Mergers Going Notts: Challenges for Modern Halo Finders: Merging haloes with similar masses (i.e., major mergers) pose significant challenges for halo finders. We compare five halo finding algorithms' (AHF, HBT, Rockstar, SubFind, and VELOCIraptor) recovery of halo properties for both isolated and cosmological ma...
A Simple Analytic Treatment of Linear Growth of Structure with Baryon Acoustic Oscillations: In linear perturbation theory, all information about the growth of structure is contained in the Green's function, or equivalently, transfer function. These functions are generally computed using numerical codes or by phenome...
Beyond the plane-parallel and Newtonian approach: Wide-angle redshift distortions and convergence in general relativity: We extend previous analyses of wide-angle correlations in the galaxy power spectrum in redshift space to include all general relativistic effects. These general relativistic corrections to the stan...
Kinematics of Arp 270: gas flows, nuclear activity and two regimes of star formation: We have observed the Arp 270 system (NGC 3395 & NGC 3396) in H{\alpha} emission using the GH{\alpha}FaS Fabry-Perot spectrometer on the 4.2m William Herschel Telescope (La Palma). In NGC 3396, which is edge-on to us, we detect gas i...
The 6dF Galaxy Survey: z \approx 0 measurement of the growth rate and sigma_8: We present a detailed analysis of redshift-space distortions in the two-point correlation function of the 6dF Galaxy Survey (6dFGS). The K-band selected sub-sample which we employ in this study contains 81971 galaxies distributed over 1700...
The Stellar Halos of Massive Elliptical Galaxies: We use the Mitchell Spectrograph (formerly VIRUS-P) on the McDonald Observatory 2.7m Harlan J. Smith Telescope to search for the chemical signatures of massive elliptical galaxy assembly. The Mitchell Spectrograph is an integral-field spectrograph with a uniquely wide f...
The NIKA2 Sunyaev-Zeldovich Large Program: The NIKA2 Guaranteed-Time SZ Large Program (LPSZ) is dedicated to the high-angular resolution SZ mapping of a representative sample of 45 SZ-selected galaxy clusters drawn from the catalogues of the Planck satellite, or of the Atacama Cosmology Telescope. The LPSZ sample spans...
The GALEX Arecibo SDSS Survey. VI. Second Data Release and Updated Gas Fraction Scaling Relations: We present the second data release from the GALEX Arecibo SDSS Survey (GASS), an ongoing large Arecibo program to measure the HI properties for an unbiased sample of ~1000 galaxies with stellar masses greater than 10^10...
Evidence against Ryskin's model of cosmic acceleration: In this paper I examine how well Ryskin's model of emergent cosmic acceleration fits several sets of cosmological observations. I find that while Ryskin's model is somewhat compatible with the standard model of cosmological acceleration ($\Lambda$CDM) for low reds...
Implicit Priors in Galaxy Cluster Mass and Scaling Relation Determinations: Deriving the total masses of galaxy clusters from observations of the intracluster medium (ICM) generally requires some prior information, in addition to the assumptions of hydrostatic equilibrium and spherical symmetry. Often, this informati...
Vector Galileon and inflationary magnetogenesis: Cosmological inflation provides the initial conditions for the structure formation. However, the origin of large-scale magnetic fields cannot be addressed in this framework. The key issue for this long-standing problem is the conformal invariance of the electromagnetic (...
Testing the lognormality of the galaxy and weak lensing convergence distributions from Dark Energy Survey maps: It is well known that the probability distribution function (PDF) of galaxy density contrast is approximately lognormal; whether the PDF of mass fluctuations derived from weak lensing convergence (kappa_WL)...
Hyper Suprime-Cam Year 3 Results: Measurements of Clustering of SDSS-BOSS Galaxies, Galaxy-Galaxy Lensing and Cosmic Shear: We use the Sloan Digital Sky Survey (SDSS) BOSS galaxies and their overlap with approximately 416 sq. degree of deep $grizy$-band imaging from the Subaru Hyper Suprime-Cam Survey (HSC). We measu...
Gravitational instabilities of isothermal spheres in the presence of a cosmological constant: Gravitational instabilities of isothermal spheres are studied in the presence of a positive or negative cosmological constant, in the Newtonian limit. In gravity, the statistical ensembles are not equivalent. We perform the ...
Effects of discontinuities of the derivatives of the inflaton potential: We study the effects of a class of features of the inflaton potential, corresponding to discontinuties in its derivatives. We perform fully numerical calculations and derive analytical approximations for the curvature pertubations spectrum and the...
How to generate a significant effective temperature for cold dark matter, from first principles: I show how to reintroduce velocity dispersion into perturbation theory (PT) calculations of structure in the Universe, i.e., how to go beyond the pressureless fluid approximation, starting from first principles. This addr...
Ripped ΛCDM: an observational contender to the consensus cosmological model: Current observations do not rule out the possibility that the Universe might end up in an abrupt event. Different such scenarios may be explored through suitable parameterizations of the dark energy and then confronted to cosmological backgr...
The stellar mass - halo mass relation from galaxy clustering in VUDS: a high star formation efficiency at z~3: The relation between the galaxy stellar mass M_star and the dark matter halo mass M_h gives important information on the efficiency in forming stars and assembling stellar mass in galaxies. We present the st...
Search for Wormhole Candidates: Accreting Wormholes with Monopole Magnetic Fields: The existence of even the simplest magnetized wormholes may lead to observable consequences. In the case where both the wormhole and the magnetic field around its mouths are static and spherically symmetric, and gas in the region near ...
Shedding Light on the Galaxy Luminosity Function: From as early as the 1930s, astronomers have tried to quantify the statistical nature of the evolution and large-scale structure of galaxies by studying their luminosity distribution as a function of redshift - known as the galaxy luminosity function (LF). Accurately co...
Newtonian acceleration scales in spiral galaxies: We revisit the issue of the constancy of the dark matter (DM) and baryonic Newtonian acceleration scales within the DM scale radius by considering a large sample of late - type galaxies. We rely on a Markov Chain Monte Carlo (MCMC) method to estimate the parameters of t...
Lensing reconstruction from a patchwork of polarization maps: The lensing signals involved in CMB polarization maps have already been measured with ground-based experiments such as SPTpol and POLARBEAR, and would become important as a probe of cosmological and astrophysical issues in the near future. Sizes of polarizat...
Constraining galactic structures of mirror dark matter: The simplest model of mirror sector dark matter maintains exact mirror symmetry, but has a baryon abundance $\Omega_{b'} = \beta \Omega_b$ and a suppressed temperature $T' = x T$ in the mirror sector; hence it depends only on two parameters, $\beta,x$. For suffici...
Signatures of Primordial non-Gaussianities in the Matter Power-Spectrum and Bispectrum: the Time-RG Approach: We apply the time-renormalization group approach to study the effect of primordial non-Gaussianities in the non-linear evolution of cosmological dark matter density perturbations. This method improves the sta...
Evolution of the u-band luminosity function from redshift 1.2 to 0: We produce and analyse u-band luminosity functions for the red and blue populations of galaxies using data from the Sloan Digital Sky Survey (SDSS) u-band Galaxy Survey (uGS) and Deep Evolutionary Exploratory Probe 2 (DEEP2) survey. From a spectroscopi...
Colour Gradients and the Colour-Magnitude Relation: Different Properties of Brightest Cluster Galaxies and E/S0 Galaxies in the Sloan Digital Sky Survey: We examine the colour-magnitude relation of approximately 5000 Brightest Cluster Galaxies (BCGs) in the Sloan Digital Sky Survey, and compare with non-BCG E/S0 ga...
Galaxy Pairs in the Local Group: Current models of galaxy formation predict that galaxy pairs of comparable magnitudes should become increasingly rare with decreasing luminosity. This seems at odds with the relatively high frequency of pairings among dwarf galaxies in the Local Group. We use literature data to show tha...
Discovery and Follow-up of a Nearby Galaxy from the Arecibo Zone of Avoidance Survey: The Arecibo L-Band Feed Array Zone of Avoidance (ALFA ZOA) Survey has discovered a nearby galaxy, ALFA ZOA J1952+1428, at a heliocentric velocity of +279 km s-1. The galaxy was discovered at low Galactic latitude by 21-cm emission f...
Primordial black hole formation by vacuum bubbles II: The discoveries of LIGO/Virgo black holes in recent years have revitalized the study of primordial black holes. In this work, we investigate a mechanism where primordial black holes are formed by vacuum bubbles that randomly nucleate during inflation through quantum...
Lyman-Alpha Emitter Galaxies at z ~ 2.8 in the Extended Chandra Deep Field-South: I. Tracing the Large-Scale Structure via Lyman-Alpha Imaging: We present a narrowband survey with three adjacent filters for z=2.8--2.9 Lyman Alpha Emitter (LAE) galaxies in the Extended Chandra Deep Field South (ECDFS), along with spec...
A direct measurement of the linear bias of mid-infrared-selected quasars at z~1 using cosmic microwave background lensing: We measure the cross-power spectrum of the projected mass density as traced by the convergence of the cosmic microwave background lensing field from the South Pole Telescope (SPT) and a sample of...
Measuring cosmic velocities with 21cm intensity mapping and galaxy redshift survey cross-correlation dipoles: We investigate the feasibility of measuring the effects of peculiar velocities in large-scale structure using the dipole of the redshift-space cross-correlation function. We combine number counts of galaxies ...
Agnostic Stacking of Intergalactic Doublet Absorption: Measuring the NeVIII Population: We present a blind search for doublet intergalactic metal absorption with a method dubbed `agnostic stacking'. Using a forward-modelling framework we combine this with direct detections in the literature to measure the overall met...
A coupled generalized three-form dark energy model: A coupled dark energy model is considered, in which dark energy is represented by a generalized three-form field and dark matter by dust. By assuming the functions $N$ and $I$ in the model's Lagrangian as two power-law functions of the three-form field, we obtain two ...
Implications of Planck2015 for inflationary, ekpyrotic and anamorphic bouncing cosmologies: The results from Planck2015, when combined with earlier observations from WMAP, ACT, SPT and other experiments, were the first observations to disfavor the "classic" inflationary paradigm. To satisfy the observational constrai...
Constraining the interaction between dark sectors with future HI intensity mapping observations: We study a model of interacting dark matter and dark energy, in which the two components are coupled. We calculate the predictions for the 21-cm intensity mapping power spectra, and forecast the detectability with future ...
Detecting the non-Gaussianity of the 21-cm signal during reionisation with the Wavelet Scattering Transform: Detecting the 21-cm hyperfine transition from neutral hydrogen in the intergalactic medium is our best probe for understanding the astrophysical processes driving the Epoch of Reionisation (EoR). The primary m...
Obscuring and feeding supermassive black holes with evolving nuclear star clusters: Recently, high resolution observations with the help of the near-infrared adaptive optics integral field spectrograph SINFONI at the VLT proved the existence of massive and young nuclear star clusters in the centres of a sample of Sey...
A point cloud approach to generative modeling for galaxy surveys at the field level: We introduce a diffusion-based generative model to describe the distribution of galaxies in our Universe directly as a collection of points in 3-D space (coordinates) optionally with associated attributes (e.g., velocities and masses...
Efficient Mass Estimate at the Core of Strong Lensing Galaxy Clusters Using the Einstein Radius: In the era of large surveys, yielding thousands of galaxy clusters, efficient mass proxies at all scales are necessary in order to fully utilize clusters as cosmological probes. At the cores of strong lensing clusters, th...
Calibrating photometric redshift measurements with the Multi-channel Imager (MCI) of the China Space Station Telescope (CSST): The China Space Station Telescope (CSST) photometric survey aims to perform a high spatial resolution (~0.15'') photometric imaging for the targets that cover a large sky area (~17,500 deg^2)...
Preferred axis in cosmology: The foundation of modern cosmology relies on the so-called cosmological principle which states an homogeneous and isotropic distribution of matter in the universe on large scales. However, recent observations, such as the temperature anisotropy of the cosmic microwave background (CMB) radia...
On the accuracy and precision of correlation functions and field-level inference in cosmology: We present a comparative study of the accuracy and precision of correlation function methods and full-field inference in cosmological data analysis. To do so, we examine a Bayesian hierarchical model that predicts log-norma...
Primordial perturbations from dilaton-induced gauge fields: We study the primordial scalar and tensor perturbations in inflation scenario involving a spectator dilaton field. In our setup, the rolling spectator dilaton causes a tachyonic instability of gauge fields, leading to a copious production of gauge fields in th...
One line to run them all: SuperEasy massive neutrino linear response in $N$-body simulations: We present in this work a novel and yet extremely simple method for incorporating the effects of massive neutrinos in cosmological $N$-body simulations. This so-called "SuperEasy linear response" approach is based upon analy...
A dynamical model for the Taffy galaxies UGC 12914/5: The spectacular head-on collision of the two gas-rich galaxies of the Taffy system, UGC 12914/15, gives us a unique opportunity to study the consequences of a direct ISM-ISM collision. To interpret existing multi-wavelength observations, we made dynamical simulation...
Modeling assembly bias with machine learning and symbolic regression: Upcoming 21cm surveys will map the spatial distribution of cosmic neutral hydrogen (HI) over unprecedented volumes. Mock catalogues are needed to fully exploit the potential of these surveys. Standard techniques employed to create these mock catalogs...
Rhapsody-G simulations: galaxy clusters as baryonic closed boxes and the covariance between hot gas and galaxies: Within a sufficiently large cosmic volume, conservation of baryons implies a simple `closed box' view in which the sum of the baryonic components must equal a constant fraction of the total enclosed mass....
Cosmological parameter inference from galaxy clustering: The effect of the posterior distribution of the power spectrum: We consider the shape of the posterior distribution to be used when fitting cosmological models to power spectra measured from galaxy surveys. At very large scales, Gaussian posterior distributions...
Evidence for a wide range of UV obscuration in z ~ 2 dusty galaxies from the GOODS-Herschel survey: Dusty galaxies at z ~ 2 span a wide range of relative brightness between rest-frame mid-infrared (8um) and ultraviolet wavelengths. We attempt to determine the physical mechanism responsible for this diversity. Dust-ob...
Cosmological parameter estimation via iterative emulation of likelihoods: The interpretation of cosmological observables requires the use of increasingly sophisticated theoretical models. Since these models are becoming computationally very expensive and display non-trivial uncertainties, the use of standard Bayesian a...
Information theory for fields: A physical field has an infinite number of degrees of freedom since it has a field value at each location of a continuous space. Therefore, it is impossible to know a field from finite measurements alone and prior information on the field is essential for field inference. An information t...
Synchronize your \textit{chrono-brane}: Testing a variable brane tension model with strong gravitational lensing: Brane world models have shown to be promising to understand the late cosmic acceleration, in particular because such acceleration can be naturally derived, mimicking the dark energy behaviour just with a ...
Impact of Polarized Galactic Foreground Emission on CMB Lensing Reconstruction and Delensing of B-Modes: Next generation CMB experiments such as CMB-S4 aim at measuring the CMB lensing potential at sub-percent precision where most of the constraining power will come from CMB polarization. We investigate the prospects...
Ultra-compact radio sources and the isotropy and homogeneity of the Universe: A 2.29 GHz VLBI all-sky survey of ultra-compact radio sources has formed the basis of a number of cosmological investigations, which examine the relationship between angular-size and redshift. Here I use a sample of 468 such sources with 0....
Patchy Screening of the Cosmic Microwave Background by Inhomogeneous Reionization: We derive a constraint on patchy screening of the cosmic microwave background from inhomogeneous reionization, using off-diagonal TB and TT correlations in WMAP-7 temperature/polarization data. We interpret this as a constraint on the ...
A template of atmospheric molecular oxygen circularly polarized emission for CMB experiments: We compute the polarized signal from atmospheric molecular oxygen due to Zeeman effect in the Earth magnetic field for various sites suitable for CMB measurements such as South Pole, Dome C (Antarctica) and Atacama desert (C...
Bias, redshift space distortions and primordial nongaussianity of nonlinear transformations: application to Lyman alpha forest: On large scales a nonlinear transformation of matter density field can be viewed as a biased tracer of the density field itself. A nonlinear transformation also modifies the redshift space d...