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2019-02-17
Finite-size effects on sound damping in stable computer glasses
In this brief note we comment on the recent results presented in arXiv:1812.08736v1
1902.06225v1
2019-05-04
A class of second-order geometric quasilinear hyperbolic PDEs and their application in imaging science
In this paper, we study damped second-order dynamics, which are quasilinear hyperbolic partial differential equations (PDEs). This is inspired by the recent development of second-order damping systems for accelerating energy decay of gradient flows. We concentrate on two equations: one is a damped second-order total va...
1905.01457v2
2019-07-08
Single-spectrum prediction of kurtosis of water waves in a non-conservative model
We study statistical properties after a sudden episode of wind for water waves propagating in one direction. A wave with random initial conditions is propagated using a forced-damped higher order Nonlinear Schr\"odinger equation (NLS). During the wind episode, the wave action increases, the spectrum broadens, the spect...
1907.03490v1
2019-08-20
Synthetic Extreme-ultraviolet Emissions Modulated by Leaky Fast Sausage Modes in Solar Active Region Loops
We study the extreme-ultraviolet (EUV) emissions modulated by leaky fast sausage modes (FSMs) in solar active region loops and examine their observational signatures via spectrometers like EIS. After computing fluid variables of leaky FSMs with MHD simulations, we forward-model the intensity and spectral properties of ...
1908.07131v1
2019-08-29
Enhancement of ultrafast demagnetization rate and Gilbert damping driven by femtosecond laser-induced spin currents in Fe81Ga19/Ir20Mn80 bilayers
In spintronics applications, ultrafast spin dynamics have to be controlled at femtosecond (fs) timescales via fs-laser radiation. At such ultrafast timescales, the effect of the Gilbert damping factor {\alpha} on ultrafast demagnetization time should be considered. In previous explorations for the relationship between ...
1908.11084v1
2019-10-24
Frequency criteria for exponential stability
We discuss some frequency-domain criteria for the exponential stability of nonlinear feedback systems based on dissipativity theory. Applications are given to convergence rates for certain perturbations of the damped harmonic oscillator.
1910.10855v2
2019-11-05
IW And-Type State in IM Eridani
IW And stars are a recently recognized group of dwarf novae which are characterized by a repeated sequence of brightening from a standstill-like phase with damping oscillations followed by a deep dip. Kimura et al. (2019) recently proposed a model based on thermal-viscous disk instability in a tilted disk to reproduce ...
1911.01587v1
2019-11-28
Magnon damping in the zigzag phase of the Kitaev-Heisenberg-$Γ$ model on a honeycomb lattice
We calculate magnon dispersions and damping in the Kitaev-Heisenberg model with an off-diagonal exchange $\Gamma$ and isotropic third-nearest-neighbor interaction $J_3$ on a honeycomb lattice. This model is relevant to a description of the magnetic properties of iridium oxides $\alpha$-Li$_2$IrO$_3$ and Na$_2$IrO$_3$, ...
1911.12829v2
2019-12-10
A Stochastic Quasi-Newton Method for Large-Scale Nonconvex Optimization with Applications
This paper proposes a novel stochastic version of damped and regularized BFGS method for addressing the above problems.
1912.04456v1
2019-12-27
Ultralow mechanical damping with Meissner-levitated ferromagnetic microparticles
Levitated nanoparticles and microparticles are excellent candidates for the realization of extremely isolated mechanical systems, with a huge potential impact in sensing applications and in quantum physics. Magnetic levitation based on static fields is a particularly interesting approach, due to the unique property of ...
1912.12252v3
2020-01-22
Wide Area Measurement System-based Low Frequency Oscillation Damping Control through Reinforcement Learning
Ensuring the stability of power systems is gaining more attraction today than ever before, due to the rapid growth of uncertainties in load and renewable energy penetration. Lately, wide area measurement system-based centralized controlling techniques started providing a more flexible and robust control to keep the sys...
2001.07829v1
2020-02-13
Semi-realistic tight-binding model for spin-orbit torques
We compute the spin-orbit torque in a transition metal heterostructure using Slater-Koster parameterization in the two-center tight-binding approximation and accounting for d-orbitals only. In this method, the spin-orbit coupling is modeled within Russel-Saunders scheme, which enables us to treat interfacial and bulk s...
2002.05533v1
2020-02-14
One-dimensional wave equation with set-valued boundary damping: well-posedness, asymptotic stability, and decay rates
This paper is concerned with the analysis of a one dimensional wave equation $z_{tt}-z_{xx}=0$ on $[0,1]$ with a Dirichlet condition at $x=0$ and a damping acting at $x=1$ which takes the form $(z_t(t,1),-z_x(t,1))\in\Sigma$ for every $t\geq 0$, where $\Sigma$ is a given subset of $\mathbb R^2$. The study is performed ...
2002.06186v3
2020-03-30
Optimal absorption of acoustical waves by a boundary
In the aim to find the simplest and most efficient shape of a noise absorbing wall to dissipate the acoustical energy of a sound wave, we consider a frequency model described by the Helmholtz equation with a damping on the boundary. The well-posedness of the model is shown in a class of domains with d-set boundaries (N...
2003.13250v2
2020-04-24
Suppression of the longitudinal coupled bunch instability in DA$Φ$NE in collisions with a crossing angle
In DAFNE, the Frascati $e^+e^-$ collider operating since 1998, an innovative collision scheme, the crab waist, has been successfully implemented during the years 2008-09. During operations for the Siddharta experiment an unusual synchrotron oscillation damping effect induced by beam-beam collisions has been observed. I...
2004.11902v1
2020-05-08
Separatrix crossing and symmetry breaking in NLSE-like systems due to forcing and damping
We theoretically and experimentally examine the effect of forcing and damping on systems that can be described by the nonlinear Schr\"odinger equation (NLSE), by making use of the phase-space predictions of the three-wave truncation of the spectrum. In the latter, only the fundamental frequency and the upper and lower ...
2005.03931v1
2020-05-13
Damping of a micro-electromechanical oscillator in turbulent superfluid $^4$He: A novel probe of quantized vorticity in the ultra-low temperature regime
We report a comprehensive investigation of the effects of quantum turbulence and quantized vorticity in superfluid $^4$He on the motion of a micro-electromechanical systems (MEMS) resonator. We find that the MEMS is uniquely sensitive to quantum turbulence present in the fluid. To generate turbulence in the fluid, a qu...
2005.06570v1
2020-06-10
Online PMU-Based Wide-Area Damping Control for Multiple Inter-Area Modes
This paper presents a new phasor measurement unit (PMU)-based wide-area damping control (WADC) method to suppress the critical inter-area modes of large-scale power systems. Modal participation factors, estimated by a practically model-free system identification approach, are used to select the most suitable synchronou...
2006.05651v1
2020-06-14
A general formulation for the magnetic oscillations in two dimensional systems
We develop a general formalism for the magnetic oscillations (MO) in two dimensional (2D) systems. We consider general 2D Landau levels, which may depend on other variable or indices, besides the perpendicular magnetic field. In the ground state, we obtain expressions for the MO phase and amplitude. From this we use a ...
2006.07944v2
2020-08-03
Improvement on the blow-up of the wave equation with the scale-invariant damping and combined nonlinearities
We consider in this article the damped wave equation, in the \textit{scale-invariant case} with combined two nonlinearities, which reads as follows: \begin{displaymath} \d (E) \hspace{1cm} u_{tt}-\Delta u+\frac{\mu}{1+t}u_t=|u_t|^p+|u|^q, \quad \mbox{in}\ \R^N\times[0,\infty), \end{displaymath} with small initial data....
2008.02109v3
2020-08-26
Quantum Lifshitz points and fluctuation-induced first-order phase transitions in imbalanced Fermi mixtures
We perform a detailed analysis of the phase transition between the uniform superfluid and normal phases in spin- and mass-imbalanced Fermi mixtures. At mean-field level we demonstrate that at temperature $T\to 0$ the gradient term in the effective action can be tuned to zero for experimentally relevant sets of paramete...
2008.11782v1
2020-09-10
Electron Landau Damping of Kinetic Alfvén Waves in Simulated Magnetosheath Turbulence
Turbulence is thought to play a role in the heating of the solar wind plasma, though many questions remain to be solved regarding the exact nature of the mechanisms driving this process in the heliosphere. In particular, the physics of the collisionless interactions between particles and turbulent electromagnetic field...
2009.05010v1
2020-11-09
Plasmon energy losses in shear bands of metallic glass
Shear bands resulting from plastic deformation in cold-rolled Al$_{88}$Y$_{7}$Fe$_{5}$ metallic glass were observed to display alternating density changes along their propagation direction. Electron-energy loss spectroscopy (EELS) was used to investigate the volume plasmon energy losses in and around shear bands. Energ...
2011.04396v3
2020-12-04
Quantum Circuits for Collective Amplitude Damping in Two-Qubit Systems
Quantum computers have now appeared in our society and are utilized for the investigation of science and engineering. At present, they have been built as intermediate-size computers containing about fifty qubits and are weak against noise effects. Hence, they are called noisy-intermediate scale quantum devices. In orde...
2012.02410v1
2020-12-10
Dimensional analysis of spring-wing systems reveals performance metrics for resonant flapping-wing flight
Flapping-wing insects, birds, and robots are thought to offset the high power cost of oscillatory wing motion by using elastic elements for energy storage and return. Insects possess highly resilient elastic regions in their flight anatomy that may enable high dynamic efficiency. However, recent experiments highlight l...
2012.05428v1
2021-01-22
Measurements and analysis of response function of cold atoms in optical molasses
We report our experimental measurements and theoretical analysis of the position response function of a cloud of cold atoms residing in the viscous medium of an optical molasses and confined by a magneto-optical trap (MOT). We measure the position response function by applying a transient homogeneous magnetic field as ...
2101.09118v2
2021-03-11
Nontrivial damping of quantum many-body dynamics
Understanding how the dynamics of a given quantum system with many degrees of freedom is altered by the presence of a generic perturbation is a notoriously difficult question. Recent works predict that, in the overwhelming majority of cases, the unperturbed dynamics is just damped by a simple function, e.g., exponentia...
2103.06646v2
2021-03-24
Multimode piezoelectric shunt damping of thin plates with arrays of separately shunted patches, method, and experimental validation
Two-dimensional thin plates are widely used in many applications. Shunt damping is a promising way for the attenuation of vibration of these electromechanical systems. It enables a compact vibration damping method without adding significant mass and volumetric occupancy. Analyzing the dynamics of such electromechanical...
2103.13179v1
2021-03-29
Nonequilibrium Dynamics of the Chiral Quark Condensate under a Strong Magnetic Field
Strong magnetic fields impact quantum-chromodynamics (QCD) properties in several situations; examples include the early universe, magnetars, and heavy-ion collisions. These examples share a common trait: time evolution. A prominent QCD property impacted by a strong magnetic field is the quark condensate, an approximate...
2103.15665v1
2021-04-09
Taming the pinch singularities in the two-loop neutrino self-energy in a medium
We consider the calculation of the thermal self-energy of a neutrino that propagates in a medium composed of fermions and scalars interacting via a Yukawa-type coupling, in the case that the neutri no energy is much larger than the fermion and scalar masses, as well as the temperature and chemical potentials of the bac...
2104.04459v2
2021-06-16
Spin-Torque-driven Terahertz Auto Oscillations in Non-Collinear Coplanar Antiferromagnets
We theoretically and numerically study the terahertz auto oscillations in thin-film metallic non-collinear coplanar antiferromagnets (AFMs), such as $\mathrm{Mn_{3}Sn}$ and $\mathrm{Mn_{3}Ir}$, under the effect of anti-damping spin-torque with spin polarization perpendicular to the plane of the film. To obtain the orde...
2106.08528v2
2021-06-20
Life-cycle assessment for flutter probability of a long-span suspension bridge based on field monitoring data
Assessment of structural safety status is of paramount importance for existing bridges, where accurate evaluation of flutter probability is essential for long-span bridges. In current engineering practice, at the design stage, flutter critical wind speed is usually estimated by the wind tunnel test, which is sensitive ...
2106.10694v1
2021-07-17
Theoretical and numerical study of vibrational resonance in a damped softening Duffing oscillator
We study the possibility of occurrence of vibrational resonance in a softening Duffing oscillator in the underdamped and overdamped cases both theoretically as well as numerically. The oscillator is driven by two periodic forces. Numerically we find that in the underdamped case two oscillatory solutions are obtained in...
2107.08302v1
2021-07-28
Optimal gamma-ray selections for monochromatic line searches with DAMPE
The DArk Matter Particle Explorer (DAMPE) is a space high-energy cosmic-ray detector covering a wide energy band with a high energy resolution. One of the key scientific goals of DAMPE is to carry out indirect detection of dark matter by searching for high-energy gamma-ray line structure. To promote the sensitivity of ...
2107.13208v2
2021-07-28
Magnetic field induced asymmetric splitting of the output signal
In this paper we have investigated the dynamics of a damped harmonic oscillator in the presence of an electromagnetic field. The transients for the two dimensional harmonic oscillator imply about the modulation of the frequency of the oscillator by the velocity dependent non conservative force from an applied magnetic ...
2107.13305v1
2021-07-31
Oscillating scalar dissipating in a medium
We study how oscillations of a scalar field condensate are damped due to dissipative effects in a thermal medium. Our starting point is a non-linear and non-local condensate equation of motion descending from a 2PI-resummed effective action derived in the Schwinger-Keldysh formalism appropriate for non-equilibrium quan...
2108.00254v1
2021-08-02
Large-amplitude longitudinal oscillations in solar prominences simulated with different resolutions
Large-amplitude longitudinal oscillations (LALOs) in solar prominences have been widely studied in the last decades. However, their damping and amplification mechanisms are not well understood. In this study, we investigate the attenuation and amplification of LALOs using high-resolution numerical simulations with prog...
2108.01143v1
2021-08-05
Complexity analysis of quantum teleportation via different entangled channels in the presence of noise
Quantum communication is one of the hot topics in quantum computing, where teleportation of a quantum state has a slight edge and gained significant attention from researchers. A large number of teleportation schemes have already been introduced so far. Here, we compare the teleportation of a single qubit message among...
2108.02641v1
2021-08-06
Noncontact friction: Role of phonon damping and its nonuniversality
While obtaining theoretical predictions for dissipation during sliding motion is a difficult task, one regime that allows for analytical results is the so-called noncontact regime, where a probe is weakly interacting with the surface over which it moves. Studying this regime for a model crystal, we extend previously ob...
2108.03025v3
2021-09-14
Design of a HOM-Damped 166.6 MHz Compact Quarter-Wave beta=1 Superconducting Cavity for High Energy Photon Source
Superconducting cavities with low RF frequencies and heavy damping of higher order modes (HOM) are desired for the main accelerator of High Energy Photon Source (HEPS), a 6 GeV synchrotron light source promising ultralow emittance currently under construction in Beijing. A compact 166.6 MHz superconducting cavity was p...
2109.06560v1
2021-11-13
Effects of microplastics and surfactants on surface roughness of water waves
In this paper, we study the flow physics underlying the recently developed remote sensing capability of detecting oceanic microplastics, which is based on the measurable surface roughness reduction induced by the presence of microplastics on the ocean surface. In particular, we are interested in whether this roughness ...
2111.07021v1
2021-11-17
United Nation Security Council in Quantum World: Experimental Realization of Quantum Anonymous Veto Protocols using IBM Quantum Computer
United Nation (UN) security council has fifteen members, out of which five permanent members of the council can use their veto power against any unfavorable decision taken by the council. In certain situation, a member using right to veto may prefer to remain anonymous. This need leads to the requirement of the protoco...
2111.09028v1
2021-12-03
The Importance of Electron Landau Damping for the Dissipation of Turbulent Energy in Terrestrial Magnetosheath Plasma
Heliospheric plasma turbulence plays a key role in transferring the energy of large-scale magnetic field and plasma flow fluctuations to smaller scales where the energy can be dissipated, ultimately leading to plasma heating. High-quality measurements of electromagnetic fields and electron velocity distributions by the...
2112.02171v1
2022-01-01
Extremely strong DLAs at high redshift: Gas cooling and H$_2$ formation
We present a spectroscopic investigation with VLT/X-shooter of seven candidate extremely strong damped Lyman-$\alpha$ absorption systems (ESDLAs, $N(\text{HI})\ge 5\times 10^{21}$ cm$^{-2}$) observed along quasar sightlines. We confirm the extremely high column densities, albeit slightly (0.1~dex) lower than the origin...
2201.00245v1
2022-01-05
Stability of the discrete time-crystalline order in spin-optomechanical and open cavity QED systems
Discrete time crystals (DTC) have been demonstrated experimentally in several different quantum systems in the past few years. Spin couplings and cavity losses have been shown to play crucial roles for realizing DTC order in open many-body systems out of equilibrium. Recently, it has been proposed that eternal and tran...
2201.01568v2
2022-01-20
Sharp resolvent estimate for the Baouendi-Grushin operator and applications
In this article we study the semiclassical resolvent estimate for the non-selfadjoint Baouendi-Grushin operator on the two-dimensional torus $\mathbb{T}^2=\mathbb{R}^2/(2\pi\mathbb{Z})^2$ with H\"older dampings. The operator is subelliptic degenerating along the vertical direction at $x=0$. We exhibit three different s...
2201.08189v2
2022-02-24
Coherence of ion cyclotron resonance for damping ion cyclotron waves in space plasmas
Ion cyclotron resonance is one of the fundamental energy conversion processes through field-particle interaction in collisionless plasmas. However, the key evidence for ion cyclotron resonance (i.e., the coherence between electromagnetic fields and the ion phase space density) and the resulting damping of ion cyclotron...
2202.11967v1
2022-03-15
Search for gamma-ray line signals around the black hole at the galactic center with DAMPE observation
The adiabatic growth of a black hole (BH) may enhance the dark matter (DM) density surrounding it, causing a spike in the DM density profile. The spike around the supermassive BH at the center of the Milky Way may lead to a dramatic enhancement of the gamma-ray flux of DM annihilation from the galactic center (GC). In ...
2203.08078v1
2022-03-15
Optimal Damping with Hierarchical Adaptive Quadrature for Efficient Fourier Pricing of Multi-Asset Options in Lévy Models
Efficiently pricing multi-asset options is a challenging problem in quantitative finance. When the characteristic function is available, Fourier-based methods are competitive compared to alternative techniques because the integrand in the frequency space often has a higher regularity than that in the physical space. Ho...
2203.08196v4
2022-03-25
Nonlinear damped spatially periodic breathers and the emergence of soliton-like rogue waves
The spatially periodic breather solutions (SPBs) of the nonlinear Schr\"odinger equation, prominent in modeling rogue waves, are unstable. In this paper we numerically investigate the effects of nonlinear dissipation and higher order nonlinearities on the routes to stability of the SPBs in the framework of the nonlinea...
2203.13488v2
2022-03-25
Investigating the effect of noise channels on the quality of unitary t-designs
Unitary t-designs have a wide variety of applications in quantum information theory, such as quantum data encryption and randomised benchmarking. However, experimental realisations of t-designs are subject to noise. Here we investigate the effect of noise channels on the quality of single-qubit t-designs. The noise cha...
2203.13771v2
2022-04-25
Geometrical aspects of contact mechanical systems and field theories
Many important theories in modern physics can be stated using differential geometry. Symplectic geometry is the natural framework to deal with autonomous Hamiltonian mechanics. This admits several generalizations for nonautonomous systems, both regular and singular. Some of these extensions are the subject of this thes...
2204.11537v1
2022-06-20
Swinging a playground swing: torque controls for inducing sustained oscillations
Models of a playground swing have been studied since the 1960s. However, in most of them, the position of the swinger is controlled directly. This simplifies the problem but hides the mechanics of torques applied to keep the swing moving in a regular pattern. This article studies these mechanics. Two models of a swing ...
2206.09579v1
2022-07-01
Frequency beating and damping of breathing oscillations of a harmonically trapped one-dimensional quasicondensate
We study the breathing (monopole) oscillations and their damping in a harmonically trapped one-dimensional (1D) Bose gas in the quasicondensate regime using a finite-temperature classical field approach. By characterising the oscillations via the dynamics of the density profile's rms width over long time, we find that ...
2207.00209v2
2022-07-29
Coordinated control in multi-terminal VSC-HVDC systems to improve transient stability: Impact on electromechanical-oscillation damping
Multi-terminal high-voltage Direct Current technology based on Voltage-Source Converter stations (VSC-MTDC) is expected to be one of the most important contributors to the future of electric power systems. In fact, among other features, it has already been shown how this technology can contribute to improve transient s...
2208.00083v1
2022-08-04
Thermoelastic Damping in MEMS Gyroscopes at High Frequencies
Microelectromechanical systems (MEMS) gyroscopes are widely used, e.g. in modern automotive and consumer applications, and require signal stability and accuracy in rather harsh environmental conditions. In many use cases, device reliability must be guaranteed under large external loads at high frequencies. The sensitiv...
2208.02591v2
2022-08-02
Motion of a parametrically driven damped coplanar double pendulum
We present the results of linear stability of a damped coplanar double pendulum and its non-linear motion, when the point of suspension is vibrated sinusoidally in the vertical direction with amplitude $a$ and frequency $\omega $. A double pendulum has two pairs of Floquet multipliers, which have been calculated for va...
2208.03292v2
2022-08-09
Simultaneous measurements of unstable and stable Alfvén Eigenmodes in JET
In this paper, we report the novel experimental observation of both unstable and stable Toroidicity-induced Alfv\'en Eigenmodes (TAEs) measured simultaneously in a JET tokamak plasma. The three-ion-heating scheme (D-DNBI-3He) is employed to accelerate deuterons to MeV energies, thereby destabilizing TAEs with toroidal ...
2208.05052v1
2022-09-24
Deep Attentive Belief Propagation: Integrating Reasoning and Learning for Solving Constraint Optimization Problems
Belief Propagation (BP) is an important message-passing algorithm for various reasoning tasks over graphical models, including solving the Constraint Optimization Problems (COPs). It has been shown that BP can achieve state-of-the-art performance on various benchmarks by mixing old and new messages before sending the n...
2209.12000v1
2022-12-01
Slack-based tunable damping leads to a trade-off between robustness and efficiency in legged locomotion
Animals run robustly in diverse terrain. This locomotion robustness is puzzling because axon conduction velocity is limited to a few ten meters per second. If reflex loops deliver sensory information with significant delays, one would expect a destabilizing effect on sensorimotor control. Hence, an alternative explanat...
2212.00475v1
2022-12-22
Spin wave dispersion of ultra-low damping hematite ($α\text{-Fe}_2\text{O}_3$) at GHz frequencies
Low magnetic damping and high group velocity of spin waves (SWs) or magnons are two crucial parameters for functional magnonic devices. Magnonics research on signal processing and wave-based computation at GHz frequencies focussed on the artificial ferrimagnetic garnet Y$_3$Fe$_5$O$_{12}$ (YIG) so far. We report on spi...
2212.11887v2
2023-01-19
Magnetoreological spring as element of vibration control system of dynamicly active equipment for biofuel production
The development of vibration protection systems that ensure efficiency and safety in the operation of process equipment and pipelines is one of the main tasks of controlling the dynamic state of machines. One of the effective methods of vibration isolation of the equipment of these installations is the use of vibration...
2301.07911v1
2023-01-30
Investigation of Ultrafast Demagnetization and Gilbert Damping and their Correlation in Different Ferromagnetic Thin Films Grown Under Identical Conditions
Following the demonstration of laser-induced ultrafast demagnetization in ferromagnetic nickel, several theoretical and phenomenological propositions have sought to uncover its underlying physics. In this work we revisit the three temperature model (3TM) and the microscopic three temperature model (M3TM) to perform a c...
2301.12797v1
2023-02-19
Collective Quantum Approach to Surface Plasmon Resonance Effect
In this research we present a theory of the surface plasmon resonance (SPR) effect based on the dual length-scale driven damped collective quantum oscillations of the spill-out electrons in plasmonic material surface. The metallic electron excitations are modeled using the Hermitian effective Schr\"{o}dinger-Poisson sy...
2302.13974v1
2023-03-01
Evolution of the eccentricity and inclination of low-mass planets subjected to thermal forces: a numerical study
By means of three dimensional, high resolution hydrodynamical simulations we study the orbital evolution of weakly eccentric or inclined low-mass protoplanets embedded in gaseous discs subject to thermal diffusion. We consider both non-luminous planets, and planets that also experience the radiative feedback from their...
2303.00867v1
2023-03-13
Discriminative sEMG-based features to assess damping ability and interpret activation patterns in lower-limb muscles of ACLR athletes
Objective: The main goal of the athletes who undergo anterior cruciate ligament reconstruction (ACLR) surgery is a successful return-to-sport. At this stage, identifying muscular deficits becomes important. Hence, in this study, three discriminative features based on surface electromyographic signals (sEMG) acquired in...
2303.06954v1
2023-03-28
Search for damped oscillating structures from charged pion electromagnetic form factor data
The damped oscillating structures recently revealed by a three parametric formula from the proton ``effective'' form factor data extracted of the measured total cross section $\sigma^{bare}_{tot}(e^+e^-\to p\bar p)$ still seem to have an unknown origin. The conjectures of their direct manifestation of the quark-gluon s...
2303.16681v1
2023-05-15
Landau damping and the survival threshold
In this paper, we establish the large time asymptotic behavior of solutions to the linearized Vlasov-Poisson system near general spatially homogenous equilibria $\mu(\frac12|v|^2)$ with connected support on the whole space $\RR^3_x \times \RR^3_v$, including those that are non-monotone. The problem can be solved comple...
2305.08672v1
2023-06-04
Large Dynamical Tide Amplitudes from Small Kicks at Pericenter
The effect of dynamical tide ``kicks" on eccentric binary orbits is considered using the orbital mapping method. It is demonstrated that when mode damping is negligible the mode amplitude will generically grow in time for all values of orbital eccentricity and semi-major axis, even for small kicks outside the regime ex...
2306.02382v1
2023-06-16
Damping of MHD Turbulence in A Partially Ionized Medium
The coupling state between ions and neutrals in the interstellar medium plays a key role in the dynamics of magnetohydrodynamic (MHD) turbulence, but is challenging to study numerically. In this work, we investigate the damping of MHD turbulence in a partially ionized medium using 3D two-fluid (ions+neutrals) simulatio...
2306.10010v2
2023-07-24
BGO quenching effect on spectral measurements of cosmic-ray nuclei in DAMPE experiment
The Dark Matter Particle Explorer (DAMPE) is a satellite-borne detector designed to measure high energy cosmic-rays and $\gamma$-rays. As a key sub-detector of DAMPE, the Bismuth Germanium Oxide (BGO) imaging calorimeter is utilized to measure the particle energy with a high resolution. The nonlinear fluorescence respo...
2307.12629v1
2023-08-04
Interplay of space charge, intrabeam scattering and synchrotron radiation in the Compact Linear Collider damping rings
Future ultra-low emittance rings for electron/positron colliders requiring extremely high beam brightness can be limited by collective effects. In this paper, the interplay of effects such as synchrotron radiation, intra-beam scattering (IBS) and space charge in the vicinity of excited betatron resonances is assessed. ...
2308.02196v3
2023-08-04
Nonlinear wave damping by Kelvin-Helmholtz instability induced turbulence
Magnetohydrodynamic kink waves naturally form as a consequence of perturbations to a structured medium, for example transverse oscillations of coronal loops. Linear theory has provided many insights in the evolution of linear oscillations, and results from these models are often applied to infer information about the s...
2308.02217v2
2023-08-10
JWST observations of galaxy damping wings during reionization interpreted with cosmological simulations
Spectra of the highest redshift galaxies taken with JWST are now allowing us to see into the heart of the reionization epoch. Many of these observed galaxies exhibit strong damping wing absorption redward of their Lyman-$\alpha$ emission. These observations have been used to measure the redshift evolution of the neutra...
2308.05800v1
2023-08-23
Dynamics of pinned quantized vortices in superfluid $^4$He in a microelectromechanical oscillator
We numerically studied the vortex dynamics at zero temperature in superfluid $^4$He confined between two parallel rough solid boundaries, one of which oscillates in a shear mode. This study was motivated by the experimental work by Barquist $et$ $al.$ which employed a microelectromechanical systems (MEMS) oscillator op...
2308.11942v2
2023-12-29
Modeling polyelectrolyte hydration from a multi scale polarizable pseudo particle solvent coarse grained approach
We investigate the reliability of simulations of polyelectrolyte systems in aqueous environments, simulations that are performed using an efficient multi scale coarse grained polarizable pseudo-particle particle approach, denoted as pppl, to model the solvent water, whereas the solutes are modeled using a polarizable a...
2312.17580v1
2024-02-19
Global existence for non-homogeneous incompressible inviscid fluids in presence of Ekman pumping
In this paper, we study the global solvability of the density-dependent incompressible Euler equations, supplemented with a damping term of the form $ \mathfrak{D}_{\alpha}^{\gamma}(\rho, u) = \alpha \rho^{\gamma} u $, where $\alpha>0$ and $ \gamma \in \{0,1\} $. To some extent, this system can be seen as a simplified ...
2402.12592v1
2024-02-20
The Fundamental Parameters of Astrophysical Plasma Turbulence and its Dissipation: Nonrelativistic Limit
A specific set of dimensionless plasma and turbulence parameters is introduced to characterize the nature of turbulence and its dissipation in weakly collisional space and astrophysical plasmas. Key considerations are discussed for the development of predictive models of the turbulent plasma heating that characterize t...
2402.12829v1
2024-03-06
Universality of pseudo-Goldstone damping near critical points
Recently, in studies of holographic models and hydrodynamics with spontaneous breaking of approximate symmetries, it has been proposed that the damping of pseudo-Goldstone modes at finite temperatures is universally constrained in the way that $\Omega_{\varphi}/m_{\varphi}^2\simeq D_{\varphi}$ in the broken phase, wher...
2403.03503v2
1993-11-17
Early Reionization in Cosmology
The cosmic microwave background (CMB) anisotropies have turned out to represent one of the most stringent 'bottle necks' for scenarios of large scale structure formation. As a possibility to relax this constraint, it has been proposed that early reionization can damp CMB fluctuations on small scales due to photon diffu...
9311039v1
1994-08-18
The Damping and Excitation of Galactic Warps by Dynamical Friction
We investigate the dynamical interaction of galactic warps with the surrounding dark matter halo, using analytic perturbation theory. A precessing warp induces a density wake in the collisionless dark matter, which acts back on the original warp, transferring energy and angular momentum between the warp and halo (dynam...
9408068v1
1995-09-14
Another Look at Gaussian Isocurvature Hot Dark Matter Models For Large- Scale Structure
We examine Gaussian isocurvature hot dark matter (massive neutrino) models for large-scale structure in which the initial density perturbations are produced in the baryons with a power--law spectrum $P_B(k) = Ak^{n_B}$. We calculate the linearly-evolved power spectrum and cosmic microwave fluctuations. We find that mod...
9509075v1
1995-12-12
A radio Search for high redshift HI absorption
Ground based optical observations have yielded considerable information on the statistics of damped-lyman alpha systems. In particular these systems are known to be the dominant repository of the observed neutral gas at high redshift. However, particularly at high redshift, there is the possibility that optical observa...
9512069v1
1996-01-26
The chemical evolution of galaxies at high redshift
Observations of absorption lines in the spectra of distant QSOs offer a new approach for tracking the evolution of normal galaxies from early epochs to the present day. The damped Ly alpha systems are particularly suitable for measuring the properties of what are likely to be the progenitors of present-day luminous gal...
9601153v1
1996-07-23
A damped Ly-alpha candidate at z~0.1 toward Q 0439-433
We report on the detection of a z_gal=0.101 galaxy projected on the sky at 4.2 arcsec (or 5.2 h^{-1} kpc for q_o=0.5) from the quasar Q 0439-433 (z_em=0.594). The HST spectrum of the quasar shows strong MgII, FeII, SiII, AlII and CIV absorption lines at the same redshift as the galaxy. The equivalent width ratios of th...
9607111v2
1997-08-11
Dynamos with different formulations of a dynamic alpha-effect
We investigate the behaviour of $\alpha\Omega$ dynamos with a dynamic $\alpha$, whose evolution is governed by the imbalance between a driving and a damping term. We focus on truncated versions of such dynamo models which are often studied in connection with solar and stellar variability. Given the approximate nature o...
9708093v1
1997-11-20
ORT observations of the damped Lyman alpha system towards PKS 0201+113
We report a deep radio search with the Ooty Radio Telescope (ORT) for the redshifted 21 cm absorption line from the damped Lyman alpha system seen at redshift 3.388 against the quasar PKS 0201+113. This is currently the most distant system for which a detection of 21 cm absorption has been claimed. The present observat...
9711234v1
1998-01-28
Dynamical Tide in Solar-Type Binaries
Circularization of late-type main-sequence binaries is usually attributed to turbulent convection, while that of early-type binaries is explained by resonant excitation of g modes. We show that the latter mechanism operates in solar-type stars also and is at least as effective as convection, despite inefficient damping...
9801289v1
1998-02-06
Acoustic oscillations and viscosity
Using a simple thermo-hydrodynamic model that respects relativistic causality, we revisit the analysis of qualitative features of acoustic oscillations in the photon-baryon fluid. The growing photon mean free path introduces transient effects that can be modelled by the causal generalization of relativistic Navier-Stok...
9802074v2
2000-02-29
Metallicity Evolution in the Early Universe
Observations of the damped Lya systems provide direct measurements on the chemical enrichment history of neutral gas in the early universe. In this Letter, we present new measurements for four damped Lya systems at high redshift. Combining these data with [Fe/H] values culled from the literature, we investigate the met...
0002513v3
2000-06-02
Surveys for z > 3 Damped Lyman-alpha Absorption Systems
We have completed spectroscopic observations using LRIS on the Keck 1 telescope of 30 very high redshift quasars, 11 selected for the presence of damped Ly-alpha absorption systems and 19 with redshifts z > 3.5 not previously surveyed for absorption systems. We have surveyed an additional 10 QSOs with the Lick 120'' an...
0006044v1
2000-06-21
Constraints on the physical properties of the damped Ly-alpha system of Q0000-2619 at z = 3.054
We present the detection of CII and CII* absorption in the z = 3.0543 damped Ly-alpha system toward Q0000-2619. The derived population ratio implies a fine structure excitation temperature between 19.6 and 21.6 K. The upper value sets a strict upper limit on the CMB temperature at this redshift, which is consistent wit...
0006308v1
2001-04-10
Damping scales of neutralino cold dark matter
The lightest supersymmetric particle, most likely the neutralino, might account for a large fraction of dark matter in the Universe. We show that the primordial spectrum of density fluctuations in neutralino cold dark matter (CDM) has a sharp cut-off due to two damping mechanisms: collisional damping during the kinetic...
0104173v2
2002-05-15
Building the bridge between Damped Ly-alpha Absorbers and Lyman Break galaxies
In 2000, we started the program ``Building the Bridge between Damped Ly-alpha Absorbers and Lyman-Break Galaxies: Ly-alpha Selection of Galaxies'' at the European Southern Observatory's Very Large Telescope. This project is an attempt to use Ly-alpha selection of high-z galaxies to bridge the gap between absorption- an...
0205234v2
2002-05-23
Constraining the strength of Dark Matter Interactions from Structure Formation
We discuss the damping of primordial dark matter fluctuations, taking into account explicitly the interactions of dark matter - whatever their intensity - both with itself and with other particle species. Relying on a general classification of dark matter particle candidates, our analysis provides, from structure forma...
0205406v1
2002-06-06
A catalogue of damped Lyman alpha absorption systems and radio flux densities of the background quasars
We present a catalogue of the 322 damped Lyman alpha absorbers taken from the literature. All damped Lyman alpha absorbers are included, with no selection on redshift or quasar magnitude. Of these, 123 are candidates and await confirmation using high resolution spectroscopy. For all 322 objects we catalogue the radio p...
0206091v1
2002-11-14
Formation of small-scale structure in SUSY CDM
The lightest supersymmetric particle, most likely the lightest neutralino, is one of the most prominent particle candidates for cold dark matter (CDM). We show that the primordial spectrum of density fluctuations in neutralino CDM has a sharp cut-off, induced by two different damping mechanisms. During the kinetic deco...
0211325v1
2002-12-09
Galaxies at z=3 around Damped Ly-alpha Clouds
We are exploring the connection between damped Ly-alpha absorbers (DLAs) and Lyman break galaxies (LBGs) using deep -- (5sigma)=26 m_{AB}-- broad band imaging (UBVI) of four wide fields (0.25 sq. deg. each) obtained at the Kitt Peak 4-m telescope with MOSAIC. Each field contains a damped system at z=3. We want to add...
0212206v1
2003-04-16
Building Blocks in Hierarchical Clustering Scenarios and their Connection with Damped Ly$α$ Systems
We carried out a comprehensive analysis of the chemical properties of the interstellar medium (ISM) and the stellar population (SP) of current normal galaxies and their progenitors in a hierarchical clustering scenario. We compared the results with observations of Damped Lyman-$\alpha$ systems (DLAs) under the hypothes...
0304303v2
2003-05-16
The ESI/KeckII Damped Lya Abundance Database
This paper presents chemical abundance measurements for 37 damped Lya systems at z>2.5 observed with the Echellette Spectrograph and Imager on the KeckII telescope. We measure the HI column densities of these damped systems through Voigt profile fits to their Lya profiles and we implement the apparent optical depth met...
0305312v1