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2016-10-11
Converse theorems and the local Langlands correspondence in families
We prove a descent criterion for certain families of smooth representations of GL_n(F) (F a p-adic field) in terms of the gamma factors of pairs constructed in previous work of the second author. We then use this descent criterion, together with a theory of gamma factors for families of representations of the Weil grou...
1610.03277v1
2016-10-14
An alternative view on dissipation in turbulent flows
An original experimental setup has been elaborated in order to get a better view of turbulent flows in a von Karman geometry. The availability of a very fast camera allowed to follow in time the evolution of the flows. A surprising finding is that the development of smaller whorls ceases earlier than expected and the a...
1610.05356v2
2017-03-02
Small Superposition Dimension and Active Set Construction for Multivariate Integration Under Modest Error Demand
Constructing active sets is a key part of the Multivariate Decomposition Method. An algorithm for constructing optimal or quasi-optimal active sets is proposed in the paper. By numerical experiments, it is shown that the new method can provide sets that are significantly smaller than the sets constructed by the already...
1703.00985v1
2017-03-03
Heat conduction and the nonequilibrium stationary states of stochastic energy exchange processes
I revisit the exactly solvable Kipnis--Marchioro--Presutti model of heat conduction [J. Stat. Phys. 27 65 (1982)] and describe, for one-dimensional systems of arbitrary sizes whose ends are in contact with thermal baths at different temperatures, a systematic characterization of their non-equilibrium stationary states....
1703.01240v1
2017-03-04
Algebraic geometry codes with complementary duals exceed the asymptotic Gilbert-Varshamov bound
It was shown by Massey that linear complementary dual (LCD for short) codes are asymptotically good. In 2004, Sendrier proved that LCD codes meet the asymptotic Gilbert-Varshamov (GV for short) bound. Until now, the GV bound still remains to be the best asymptotical lower bound for LCD codes. In this paper, we show tha...
1703.01441v1
2017-03-17
A finite element approximation for the stochastic Landau--Lifshitz--Gilbert equation with multi-dimensional noise
We propose an unconditionally convergent linear finite element scheme for the stochastic Landau--Lifshitz--Gilbert (LLG) equation with multi-dimensional noise. By using the Doss-Sussmann technique, we first transform the stochastic LLG equation into a partial differential equation that depends on the solution of the au...
1703.05901v1
2017-04-12
The homology of principally directed ordered groupoids
We present some homological properties of a relation $\beta$ on ordered groupoids that generalises the minimum group congruence for inverse semigroups. When $\beta$ is a transitive relation on an ordered groupoid $G$, the quotient $G / \beta$ is again an ordered groupoid, and construct a pair of adjoint functors betwee...
1704.03689v1
2017-06-15
Absence of correlations in the energy exchanges of an exactly solvable model of heat transport with many degrees of freedom
A process based on the exactly solvable Kipnis--Marchioro--Presutti model of heat conduction [J. Stat. Phys. 27 65 (1982)] is described whereby lattice cells share their energies among many identical degrees of freedom while, in each cell, only two of them are associated with energy exchanges connecting neighbouring ce...
1706.04849v1
2017-11-29
On the local converse theorem and the descent theorem in families
We prove an analogue of Jacquet's conjecture on the local converse theorem for \ell-adic families of co-Whittaker representations of GL_n(F), where F is a finite extension of Q_p and \ell does not equal p. We also prove an analogue of Jacquet's conjecture for a descent theorem, which asks for the smallest collection of...
1711.11159v1
2018-06-23
List Decodability of Symbol-Pair Codes
We investigate the list decodability of symbol-pair codes in the present paper. Firstly, we show that list decodability of every symbol-pair code does not exceed the Gilbert-Varshamov bound. On the other hand, we are able to prove that with high probability, a random symbol-pair code can be list decoded up to the Gilbe...
1806.08992v1
2018-07-05
Volumetric performance capture from minimal camera viewpoints
We present a convolutional autoencoder that enables high fidelity volumetric reconstructions of human performance to be captured from multi-view video comprising only a small set of camera views. Our method yields similar end-to-end reconstruction error to that of a probabilistic visual hull computed using significantl...
1807.01950v2
2018-10-26
Immobilization of convex bodies in $R^n$
We extend to arbitrary finite $n$ the notion of immobilization of a convex body $O$ in $R^n$ by a finite set of points $P$ in the boundary of $O$. Because of its importance for this problem, necessary and sufficient conditions are found for the immobilization of an $n$-simplex. A fairly complete geometric description o...
1810.11381v1
2019-01-14
Groupoids and the algebra of rewriting in group presentations
Presentations of groups by rewriting systems (that is, by monoid presentations), have been fruitfully studied by encoding the rewriting system in a $2$--complex -- the Squier complex -- whose fundamental groupoid then describes the derivation of consequences of the rewrite rules. We describe a reduced form of the Squie...
1901.04348v1
2019-05-27
Tuning Free Rank-Sparse Bayesian Matrix and Tensor Completion with Global-Local Priors
Matrix and tensor completion are frameworks for a wide range of problems, including collaborative filtering, missing data, and image reconstruction. Missing entries are estimated by leveraging an assumption that the matrix or tensor is low-rank. Most existing Bayesian techniques encourage rank-sparsity by modelling fac...
1905.11496v1
2019-06-26
Fairness criteria through the lens of directed acyclic graphical models
A substantial portion of the literature on fairness in algorithms proposes, analyzes, and operationalizes simple formulaic criteria for assessing fairness. Two of these criteria, Equalized Odds and Calibration by Group, have gained significant attention for their simplicity and intuitive appeal, but also for their inco...
1906.11333v1
2020-01-14
Neural Architecture Search for Deep Image Prior
We present a neural architecture search (NAS) technique to enhance the performance of unsupervised image de-noising, in-painting and super-resolution under the recently proposed Deep Image Prior (DIP). We show that evolutionary search can automatically optimize the encoder-decoder (E-D) structure and meta-parameters of...
2001.04776v1
2020-07-18
Finslerian convolution metrics and their special classes
Here, it is introduced a concept of convolution metric in Finslerian Geometry. This convolution metric is a kind of function obtained by a given mathematical operation between two Finslerian metrics. Some basic properties of the Finslerian convolution metrics are studied. Then it is characterized Finslerian convolution...
2007.14803v3
2020-09-14
What mathematical billiards teach us about statistical physics?
We survey applications of the theory of hyperbolic (and to a lesser extent non hyperbolic) billiards to some fundamental problems of statistical physics and their mathematically rigorous derivations in the framework of classical Hamiltonian systems.
2009.06284v2
2020-11-29
Applications of the Backus-Gilbert method to linear and some non linear equations
We investigate the use of a functional analytical version of the Backus-Gilbert Method as a reconstruction strategy to get specific information about the solution of linear and slightly non-linear systems with Frech\'et derivable operators. Some a priori error estimates are shown and tested for two classes of problems:...
2011.14407v1
2021-11-30
Global weak solutions for the Landau-Lifshitz-Gilbert-Vlasov-Maxwell system coupled via emergent electromagnetic fields
Motivated by recent models of current driven magnetization dynamics, we examine the coupling of the Landau-Lifshitz-Gilbert equation and classical electron transport governed by the Vlasov-Maxwell system. The interaction is based on space-time gyro-coupling in the form of emergent electromagnetic fields of quantized he...
2111.15482v1
2022-04-02
Introduction to the Artificial Intelligence that can be applied to the Network Automation Journey
The computer network world is changing and the NetDevOps approach has brought the dynamics of applications and systems into the field of communication infrastructure. Businesses are changing and businesses are faced with difficulties related to the diversity of hardware and software that make up those infrastructures. ...
2204.00800v1
2022-05-24
Theory of the Energy Variance in a Quantum Bit
We define a new quantum Hermitian operator (namely, the energy variance operator) which is simply duplicated from the statistical definition of energy variance in classical physics. Its expectation value yields the standard deviation of the energy about the mean value of this latter. We show by use of an exact Hamilton...
2205.12763v1
2022-07-11
Quasilinear rough evolution equations
We investigate the abstract Cauchy problem for a quasilinear parabolic equation in a Banach space of the form \( du_t -L_t(u_t)u_t dt = N_t(u_t)dt + F(u_t)\cdot d\mathbf X_t \), where \( \mathbf X\) is a \( \gamma\)-H\"older rough path for \( \gamma\in(1/3,1/2)\). We explore the mild formulation that combines functiona...
2207.04787v1
2022-08-01
A Pansiot-type subword complexity theorem for automorphisms of free groups
Inspired by Pansiot's work on substitutions, we prove a similar theorem for automorphisms of a free group F of finite rank: if a right-infinite word represents an attracting fixed point of an automorphism of F, the subword complexity of X is equivalent to n, n log log n, n log n, or n^2. The proof uses combinatorial ar...
2208.00676v1
2022-08-13
May the force be with you
Modern methods in dimensionality reduction are dominated by nonlinear attraction-repulsion force-based methods (this includes t-SNE, UMAP, ForceAtlas2, LargeVis, and many more). The purpose of this paper is to demonstrate that all such methods, by design, come with an additional feature that is being automatically comp...
2208.06676v1
2022-10-26
Linearized frequency domain Landau-Lifshitz-Gilbert equation formulation
We present a general finite element linearized Landau-Lifshitz-Gilbert equation (LLGE) solver for magnetic systems under weak time-harmonic excitation field. The linearized LLGE is obtained by assuming a small deviation around the equilibrium state of the magnetic system. Inserting such expansion into LLGE and keeping ...
2210.14525v1
2022-11-10
Secure Aggregation Is Not All You Need: Mitigating Privacy Attacks with Noise Tolerance in Federated Learning
Federated learning is a collaborative method that aims to preserve data privacy while creating AI models. Current approaches to federated learning tend to rely heavily on secure aggregation protocols to preserve data privacy. However, to some degree, such protocols assume that the entity orchestrating the federated lea...
2211.06324v1
2022-12-22
Theory and construction of Quasi-Monte Carlo rules for option pricing and density estimation
In this paper we propose and analyse a method for estimating three quantities related to an Asian option: the fair price, the cumulative distribution function, and the probability density. The method involves preintegration with respect to one well chosen integration variable to obtain a smooth function of the remainin...
2212.11493v2
2022-12-22
Novel Bottomonium Results
We present the latest results from the use of the Backus-Gilbert method for reconstructing the spectra of NRQCD bottomonium mesons using anisotropic FASTSUM ensembles at non-zero temperature. We focus in particular on results from the $\eta_b$, $\Upsilon$, $\chi_{b1}$ and $h_b$ generated from Tikhonov-regularized Backu...
2212.12016v1
2022-12-30
Asymptotic stability of 2-domain walls for the Landau-Lifshitz-Gilbert equation in a nanowire with Dzyaloshinskii-Moriya interaction
We consider a ferromagnetic nanowire, with an energy functional $E$ with easy-axis in the direction $e_1$, and which takes into account the Dzyaloshinskii-Moriya interaction. We consider configurations of the magnetization which are perturbations of two well separated domain wall, and study their evolution under the La...
2212.14589v1
2023-01-12
Time Domain Verification of Differential Transmission Line Modeling Methods
The advantages and limitations of time-domain pseudo-random binary sequence (PRBS) excitation methods for system identification of individual modes within a multi-conductor transmission system are discussed. We develop the modifications necessary to standard frequency-domain transmission-line models to match time-domai...
2301.05281v1
2023-01-17
Power Supply Compensation for Capacitive Loads
As ASIC supply voltages approach one volt, the source-impedance goals for power distribution networks are driven ever lower as well. One approach to achieving these goals is to add decoupling capacitors of various values until the desired impedance profile is obtained. An unintended consequence of this approach can be ...
2301.09580v1
2023-01-17
Applications of Optimization Routines in Signal Integrity Analysis
Signal integrity analysis often involves the development of design guidelines through manual manipulation of circuit parameters and judicious interpretation of results. Such an approach can result in significant effort and sub-optimal conclusions. Optimization routines have been well proven to aid analysis across a var...
2301.10157v1
2023-01-17
High Speed Parallel Signal Crosstalk Cancellation Concept
High performance computing (HPC) systems make extensive use of high speed electrical interconnects, in routing signals among processing elements, or between processing elements and memory. Increasing bandwidth demands result in high density, parallel I/O exposed to crosstalk due to tightly coupled transmission lines. T...
2301.10170v1
2023-04-05
Elimination and Factorization
If a matrix $A$ has rank $r$, then its row echelon form (from elimination) contains the identity matrix in its first $r$ independent columns. How do we \emph{interpret the matrix} $F$ that appears in the remaining columns of that echelon form\,? $F$ multiplies those first $r$ independent columns of $A$ to give its $n-r...
2304.02659v1
2023-04-25
Jet: Multilevel Graph Partitioning on Graphics Processing Units
The multilevel heuristic is the dominant strategy for high-quality sequential and parallel graph partitioning. Partition refinement is a key step of multilevel graph partitioning. In this work, we present Jet, a new parallel algorithm for partition refinement specifically designed for Graphics Processing Units (GPUs). ...
2304.13194v2
2023-05-16
QHDL: a Low-Level Circuit Description Language for Quantum Computing
This paper proposes a descriptive language called QHDL, akin to VHDL, to program gate-based quantum computing systems. Unlike other popular quantum programming languages, QHDL targets low-level quantum computing programming and aims to provide a common framework for programming FPGAs and gate-based quantum computing sy...
2305.09419v1
2023-05-21
An Alternative Derivation of the Landau-Lifshitz-Gilbert Equation for Saturated Ferromagnets
The Landau-Lifshitz-Gilbert equation for rigid and saturated ferromagnets is derived using a two-continuum model constructed by H.F. Tiersten for elastic and saturated ferromagnets. The relevant basic laws of physics are applied systematically to the two continua or their combination. The exchange interaction is introd...
2305.18232v1
2023-06-25
Gilbert's conjecture and A new way to octonionic analytic functions from the clifford analysis
In this article we will give a affirmative answer to Gilbert's conjecture on Hardy spaces of Clifford analytic functions in upper half-space of $\mathbb{R}^8$. It depends on a explicit construction of Spinor space $\mathcal{R}_8$ and Clifford algebra $Cl_8$ by octonion algbra. What's more , it gives us an associative w...
2306.14164v1
2023-06-28
Stochastic Landau-Lifshitz-Gilbert equations for frustrated magnets under fluctuating currents
We examine a stochastic Landau-Lifshitz-Gilbert equation for a frustrated ferromagnet with competing first and second order exchange interactions exposed to deterministic and random spin transfer torques in form of transport noise. We prove the existence and pathwise uniqueness of weak martingale solutions in the energ...
2306.15843v1
2023-07-28
MDS, Hermitian Almost MDS, and Gilbert-Varshamov Quantum Codes from Generalized Monomial-Cartesian Codes
We construct new stabilizer quantum error-correcting codes from generalized monomial-Cartesian codes. Our construction uses an explicitly defined twist vector, and we present formulas for the minimum distance and dimension. Generalized monomial-Cartesian codes arise from polynomials in $m$ variables. When $m=1$ our cod...
2307.15488v1
2023-09-06
Optimal Control of the 2D Landau-Lifshitz-Gilbert Equation with Control Energy in Effective Magnetic Field
The optimal control of magnetization dynamics in a ferromagnetic sample at a microscopic scale is studied. The dynamics of this model is governed by the Landau-Lifshitz-Gilbert equation on a two-dimensional bounded domain with the external magnetic field (the control) applied through the effective field. We prove the g...
2309.02786v1
2023-09-22
Relaxed optimal control for the stochastic Landau-Lifshitz-Gilbert equation
We consider the stochastic Landau-Lifshitz-Gilbert equation, perturbed by a real-valued Wiener process. We add an external control to the effective field as an attempt to drive the magnetization to a desired state and also to control thermal fluctuations. We use the theory of Young measures to relax the given control p...
2309.12556v1
2023-11-29
Bayesian interpretation of Backus-Gilbert methods
The extraction of spectral densities from Euclidean correlators evaluated on the lattice is an important problem, as these quantities encode physical information on scattering amplitudes, finite-volume spectra, inclusive decay rates, and transport coefficients. In this contribution, we show that the Bayesian approach t...
2311.18125v1
2024-01-14
Multilevel Metamodels: A Novel Approach to Enhance Efficiency and Generalizability in Monte Carlo Simulation Studies
Metamodels, or the regression analysis of Monte Carlo simulation (MCS) results, provide a powerful tool to summarize MCS findings. However, an as of yet unexplored approach is the use of multilevel metamodels (MLMM) that better account for the dependent data structure of MCS results that arises from fitting multiple mo...
2401.07294v2
2024-02-29
Evaluating the Gilbert-Varshamov Bound for Constrained Systems
We revisit the well-known Gilbert-Varshamov (GV) bound for constrained systems. In 1991, Kolesnik and Krachkovsky showed that GV bound can be determined via the solution of some optimization problem. Later, Marcus and Roth (1992) modified the optimization problem and improved the GV bound in many instances. In this wor...
2402.18869v1
1992-06-18
Wormholes and Supersymmetry
Revisions: reference added to: G. Gilbert, {\sl Nucl.Phys.} {\bf B328}, 159 (1989)
9206072v2
1993-05-26
Musings on Magnus
The object of this paper is to describe a simple method for proving that certain groups are residually torsion-free nilpotent, to describe some new parafree groups and to raise some new problems in honour of the memory of Wilhelm Magnus.
9305201v1
2001-10-17
Expected number of distinct part sizes in a random integer composition
The asymptotics, as $n\to\infty$, for the expected number of distinct part sizes in a random composition of an integer n is obtained.
0110189v1
2003-12-29
Non-hopfian relatively free groups
To solve problems of Gilbert Baumslag and Hanna Neumann, posed in the 1960's, we construct a nontrivial variety of groups all of whose noncyclic free groups are non-hopfian.
0312491v1
2005-10-26
Winning rate in the full-information best choice problem
Following a long-standing suggestion by Gilbert and Mosteller, we derive an explicit formula for the asymptotic winning rate in the full-information problem of the best choice.
0510568v3
2007-12-20
The dark matter as a light gravitino (II)
We address the question of gravitino dark matter in the context of gauge mediated supersymmetry breaking models.
0712.3465v1
2014-02-25
Du-Hwang Characteristic Area: Catch-22
The paper is devoted to description of two interconnected mistakes generated by the gap in the Du and Hwang approach to Gilbert-Pollack Steiner ratio conjecture.
1402.6079v1
2016-06-01
Existence of arbitrarily smooth solutions of the LLG equation in 3D with natural boundary conditions
We prove that the Landau-Lifshitz-Gilbert equation in three space dimensions with homogeneous Neumann boundary conditions admits arbitrarily smooth solutions, given that the initial data is sufficiently close to a constant function.
1606.00086v1
2018-10-28
Asymptotic Gilbert-Varshamov bound on Frequency Hopping Sequences
Given a $q$-ary frequency hopping sequence set of length $n$ and size $M$ with Hamming correlation $H$, one can obtain a $q$-ary (nonlinear) cyclic code of length $n$ and size $nM$ with Hamming distance $n-H$. Thus, every upper bound on the size of a code from coding theory gives an upper bound on the size of a frequen...
1810.11757v2
2020-05-26
Reidemeister Moves in Gauss Diagrams
We provide a simple algorithm for recognizing and performing Reidemeister moves in a Gauss diagram.
2005.12957v1
2021-05-26
Lee Weight for Nonbinary Quantum Error Correction
We propose the quantum Lee weight for quantum errors, provide a Gilbert-Varshamov type bound, and a code construction for the proposed weight.
2105.12354v1
2021-09-19
Compactness of isospectral conformal Finslerian metrics set on a 3-manifold
Let F be a Finslerian metric on an n-dimensional closed manifold M. In this work, we study problems about compactness of isospectral sets of conformal Finslerian metrics when n=3.
2110.06338v2
2001-05-31
Lower bound for the quantum capacity of a discrete memoryless quantum channel
We generalize the random coding argument of stabilizer codes and derive a lower bound on the quantum capacity of an arbitrary discrete memoryless quantum channel. For the depolarizing channel, our lower bound coincides with that obtained by Bennett et al. We also slightly improve the quantum Gilbert-Varshamov bound for...
0105151v4
2007-08-30
Asymptotic improvement of the Gilbert-Varshamov bound for linear codes
The Gilbert-Varshamov bound states that the maximum size A_2(n,d) of a binary code of length n and minimum distance d satisfies A_2(n,d) >= 2^n/V(n,d-1) where V(n,d) stands for the volume of a Hamming ball of radius d. Recently Jiang and Vardy showed that for binary non-linear codes this bound can be improved to A_2(n,...
0708.4164v1
2007-09-26
Finite Element Formalism for Micromagnetism
The aim of this work is to present the details of the finite element approach we developed for solving the Landau-Lifschitz-Gilbert equations in order to be able to treat problems involving complex geometries. There are several possibilities to solve the complex Landau-Lifschitz-Gilbert equations numerically. Our metho...
0709.4153v1
2009-05-07
Heat transport in stochastic energy exchange models of locally confined hard spheres
We study heat transport in a class of stochastic energy exchange systems that characterize the interactions of networks of locally trapped hard spheres under the assumption that neighbouring particles undergo rare binary collisions. Our results provide an extension to three-dimensional dynamics of previous ones applyin...
0905.1051v1
2011-08-15
Hydrodynamics of self-alignment interactions with precession and derivation of the Landau-Lifschitz-Gilbert equation
We consider a kinetic model of self-propelled particles with alignment interaction and with precession about the alignment direction. We derive a hydrodynamic system for the local density and velocity orientation of the particles. The system consists of the conservative equation for the local density and a non-conserva...
1108.2951v1
2011-09-30
Magnetization Dynamics, Gyromagnetic Relation, and Inertial Effects
The gyromagnetic relation - i.e. the proportionality between the angular momentum $\vec L$ (defined by an inertial tensor) and the magnetization $\vec M$ - is evidence of the intimate connections between the magnetic properties and the inertial properties of ferromagnetic bodies. However, inertia is absent from the dyn...
1109.6782v1
2012-08-28
Decomposition of modified Landau-Lifshitz-Gilbert equation and corresponding analytic solutions
The Suzuki-Trotter decomposition in general allows one to divide the equation of motion of a dynamical system into smaller parts whose integration are easier than the original equation. In this study, we first rewrite by employing feasible approximations the modified Landau-Lifshitz-Gilbert equation for localized spins...
1208.5545v1
2013-11-20
Asymptotic Improvement of the Gilbert-Varshamov Bound on the Size of Permutation Codes
Given positive integers $n$ and $d$, let $M(n,d)$ denote the maximum size of a permutation code of length $n$ and minimum Hamming distance $d$. The Gilbert-Varshamov bound asserts that $M(n,d) \geq n!/V(n,d-1)$ where $V(n,d)$ is the volume of a Hamming sphere of radius $d$ in $\S_n$. Recently, Gao, Yang, and Ge showe...
1311.4925v1
2016-11-21
On the List-Decodability of Random Self-Orthogonal Codes
In 2011, Guruswami-H{\aa}stad-Kopparty \cite{Gru} showed that the list-decodability of random linear codes is as good as that of general random codes. In the present paper, we further strengthen the result by showing that the list-decodability of random {\it Euclidean self-orthogonal} codes is as good as that of genera...
1611.06673v1
2017-11-29
Linear second-order IMEX-type integrator for the (eddy current) Landau-Lifshitz-Gilbert equation
Combining ideas from [Alouges et al. (Numer. Math., 128, 2014)] and [Praetorius et al. (Comput. Math. Appl., 2017)], we propose a numerical algorithm for the integration of the nonlinear and time-dependent Landau-Lifshitz-Gilbert (LLG) equation which is unconditionally convergent, formally (almost) second-order in time...
1711.10715v1
2017-12-28
Subquadratic time encodable codes beating the Gilbert-Varshamov bound
We construct explicit algebraic geometry codes built from the Garcia-Stichtenoth function field tower beating the Gilbert-Varshamov bound for alphabet sizes at least 192. Messages are identied with functions in certain Riemann-Roch spaces associated with divisors supported on multiple places. Encoding amounts to evalua...
1712.10052v2
2018-11-15
Hilbert-Schmidt distance and entanglement witnessing
Gilbert proposed an algorithm for bounding the distance between a given point and a convex set. In this article we apply the Gilbert's algorithm to get an upper bound on the Hilbert-Schmidt distance between a given state and the set of separable states. While Hilbert Schmidt Distance does not form a proper entanglement...
1811.06599v3
2020-02-13
Age of Information with Gilbert-Elliot Servers and Samplers
We study age of information in a status updating system that consists of a single sampler, i.e., source node, that sends time-sensitive status updates to a single monitor node through a server node. We first consider a Gilbert-Elliot service profile at the server node. In this model, service times at the server node fo...
2002.05711v1
2005-08-26
Damping of MHD turbulence in Solar Flares
(Abridged) We describe the cascade of plasma waves or turbulence injected, presumably by reconnection, at scales comparable to the size of a solar flare loop to scales comparable to particle gyroradii, and evaluate their damping by various mechanisms. We show that the classical viscous damping is unimportant for magnet...
0508567v1
2011-07-27
Constraint damping for the Z4c formulation of general relativity
One possibility for avoiding constraint violation in numerical relativity simulations adopting free-evolution schemes is to modify the continuum evolution equations so that constraint violations are damped away. Gundlach et. al. demonstrated that such a scheme damps low amplitude, high frequency constraint violating mo...
1107.5539v2
1999-11-24
Damped Lyman alpha absorber and the faint end of the galaxy luminosity function at high redshift
We combine predictions for several hierarchical cosmogonies with observational evidence on damped Lyman alpha systems to establish a correspondence between the high redshift galaxy population and the properties of damped Lyman alpha systems. We assume that high redshift galaxies and damped Lyman alpha systems are hoste...
9911447v1
2003-03-13
An explicit unconditionally stable numerical method for solving damped nonlinear Schrödinger equations with a focusing nonlinearity
This paper introduces an extension of the time-splitting sine-spectral (TSSP) method for solving damped focusing nonlinear Schr\"{o}dinger equations (NLS). The method is explicit, unconditionally stable and time transversal invariant. Moreover, it preserves the exact decay rate for the normalization of the wave functio...
0303158v1
2004-11-03
Quantum probability applied to the damped harmonic oscillator
In this introductory course we sketch the framework of quantum probability in order to discuss open quantum systems, in particular the damped harmonic oscillator.
0411024v1
2006-11-23
Path integrals and wavepacket evolution for damped mechanical systems
Damped mechanical systems with various forms of damping are quantized using the path integral formalism. In particular, we obtain the path integral kernel for the linearly damped harmonic oscillator and a particle in a uniform gravitational field with linearly or quadratically damped motion. In each case, we study the ...
0611239v1
2007-07-05
Damping of bulk excitations over an elongated BEC - the role of radial modes
We report the measurement of Beliaev damping of bulk excitations in cigar shaped Bose Einstein condensates of atomic vapor. By using post selection, excitation line shapes of the total population are compared with those of the undamped excitations. We find that the damping depends on the initial excitation energy of th...
0707.0776v1
2008-09-22
Damping in 2D and 3D dilute Bose gases
Damping in 2D and 3D dilute gases is investigated using both the hydrodynamical approach and the Hartree-Fock-Bogoliubov (HFB) approximation . We found that the both methods are good for the Beliaev damping at zero temperature and Landau damping at very low temperature, however, at high temperature, the hydrodynamical ...
0809.3632v3
2008-12-08
Landau Damping and Alfven Eigenmodes of Neutron Star Torsion Oscillations
Torsion oscillations of the neutron star crust are Landau damped by the Alfven continuum in the bulk. For strong magnetic fields (in magnetars), undamped Alfven eigenmodes appear.
0812.1570v1
2010-09-24
Spatial Damping of Propagating Kink Waves in Prominence Threads
Transverse oscillations and propagating waves are frequently observed in threads of solar prominences/filaments and have been interpreted as kink magnetohydrodynamic (MHD) modes. We investigate the spatial damping of propagating kink MHD waves in transversely nonuniform and partially ionized prominence threads. Resonan...
1009.4871v1
2012-08-01
Artificial Neural Network Based Prediction of Optimal Pseudo-Damping and Meta-Damping in Oscillatory Fractional Order Dynamical Systems
This paper investigates typical behaviors like damped oscillations in fractional order (FO) dynamical systems. Such response occurs due to the presence of, what is conceived as, pseudo-damping and meta-damping in some special class of FO systems. Here, approximation of such damped oscillation in FO systems with the con...
1208.0318v1
2012-08-27
Optimization of the damped quantum search
The damped quantum search proposed in [A. Mizel, Phys. Rev. Lett., 102 150501 (2009)] was analyzed by calculating the highest possible probability of finding the target state in each iteration. A new damping parameter that depends on the number of iterations was obtained, this was compared to the critical damping param...
1208.5475v1
2013-04-03
Damping the zero-point energy of a harmonic oscillator
The physics of quantum electromagnetism in an absorbing medium is that of a field of damped harmonic oscillators. Yet until recently the damped harmonic oscillator was not treated with the same kind of formalism used to describe quantum electrodynamics in a arbitrary medium. Here we use the techniques of macroscopic QE...
1304.0977v2
2015-05-28
Damping factors for head-tail modes at strong space charge
This paper suggests how feedback and Landau damping can be taken into account for transverse oscillations of bunched beam at strong space charge.
1505.07704v1
2015-06-18
Damping of MHD turbulence in partially ionized plasma: implications for cosmic ray propagation
We study the damping from neutral-ion collisions of both incompressible and compressible magnetohydrodynamic (MHD) turbulence in partially ionized medium. We start from the linear analysis of MHD waves applying both single-fluid and two-fluid treatments. The damping rates derived from the linear analysis are then used ...
1506.05585v1
2016-02-04
Damping Evaluation for Free Vibration of Spherical Structures in Elastodynamic-Acoustic Interaction
This paper discusses the free vibration of elastic spherical structures in the presence of an externally unbounded acoustic medium. In this vibration, damping associated with the radiation of energy from the confined solid medium to the surrounding acoustic medium is observed. Evaluating the coupled system response (so...
1604.06738v1
2017-09-05
Enhancement of space-charge induced damping due to reactive impedances for head-tail modes
Landau damping of head-tail modes in bunches due to spreads in the tune shift can be a deciding factor for beam stability. We demonstrate that the coherent tune shifts due to reactive impedances can enhance the space-charge induced damping and change the stability thresholds (here, a reactive impedance implies the imag...
1709.01425v1
2018-05-21
Critical damping in nonviscously damped linear systems
In structural dynamics, energy dissipative mechanisms with non-viscous damping are characterized by their dependence on the time-history of the response velocity, mathematically represented by convolution integrals involving hereditary functions. Combination of damping parameters in the dissipative model can lead the s...
1805.08022v1
2018-11-01
Hereditary effects of exponentially damped oscillators with past histories
Hereditary effects of exponentially damped oscillators with past histories are considered in this paper. Nonviscously damped oscillators involve hereditary damping forces which depend on time-histories of vibrating motions via convolution integrals over exponentially decaying functions. As a result, this kind of oscill...
1811.00216v1
2019-08-01
The Temperature-dependent Damping of Propagating Slow Magnetoacoustic Waves
The rapid damping of slow magnetoacoustic waves in the solar corona has been extensively studied in previous years. Most studies suggest that thermal conduction is a dominant contributor to this damping, albeit with a few exceptions. Employing extreme-ultraviolet (EUV) imaging data from SDO/AIA, we measure the damping ...
1908.00384v1
2019-10-14
Decay rates for the damped wave equation with finite regularity damping
Decay rates for the energy of solutions of the damped wave equation on the torus are studied. In particular, damping invariant in one direction and equal to a sum of squares of nonnegative functions with a particular number of derivatives of regularity is considered. For such damping energy decays at rate $1/t^{2/3}$. ...
1910.06372v3
2022-07-01
Seismic Response of Yielding Structures Coupled to Rocking Walls with Supplemental Damping
Given that the coupling of a framing structure to a strong, rocking wall enforces a first-mode response, this paper investigates the dynamic response of a yielding single-degree-of-freedom oscillator coupled to a rocking wall with supplemental damping (hysteretic or linear viscous) along its sides. The full nonlinear e...
2207.00641v1
2023-03-08
Material-Geometry Interplay in Damping of Biomimetic Scale Beams
Biomimetic scale-covered substrates are architected meta-structures exhibiting fascinating emergent nonlinearities via the geometry of collective scales contacts. In spite of much progress in understanding their elastic nonlinearity, their dissipative behavior arising from scales sliding is relatively uninvestigated in...
2303.04920v1
1998-03-28
Landau damping and the echo effect in a confined Bose-Einstein condensate
Low energy collective mode of a confined Bose-Einstein condensate should demonstrate the echo effect in the regime of Landau damping. This echo is a signature of reversible nature of Landau damping. General expression for the echo profile is derived in the limit of small amplitudes of the external pulses. Several unive...
9803351v1
2000-07-10
Dephasing of Electrons on Helium by Collisions with Gas Atoms
The damping of quantum effects in the transport properties of electrons deposited on a surface of liquid helium is studied. It is found that due to vertical motion of the helium vapour atoms the interference of paths of duration $t$ is damped by a factor $\exp - (t/\tau_v)^3$. An expression is derived for the weak-loca...
0007160v1
1997-10-07
Damping rate of plasmons and photons in a degenerate nonrelativistic plasma
A calculation is presented of the plasmon and photon damping rates in a dense nonrelativistic plasma at zero temperature, following the resummation program of Braaten-Pisarski. At small soft momentum $k$, the damping is dominated by $3 \to 2$ scattering processes corresponding to double longitudinal Landau damping. The...
9710260v1
2002-12-16
Influence of damping on the vanishing of the electro-optic effect in chiral isotropic media
Using first principles, it is demonstrated that radiative damping alone cannot lead to a nonvanishing electro-optic effect in a chiral isotropic medium. This conclusion is in contrast with that obtained by a calculation in which damping effects are included using the standard phenomenological model. We show that these ...
0212089v1
2005-08-28
Simultaneous amplitude and phase damping of a kind of Gaussian states and their separability
We give out the time evolution solution of simultaneous amplitude and phase damping for any continuous variable state. For the simultaneous amplitude and phase damping of a wide class of two- mode entangled Gaussian states, two analytical conditions of the separability are given. One is the sufficient condition of sepa...
0508209v2
2007-05-14
Identification of the dominant precession damping mechanism in Fe, Co, and Ni by first-principles calculations
The Landau-Lifshitz equation reliably describes magnetization dynamics using a phenomenological treatment of damping. This paper presents first-principles calculations of the damping parameters for Fe, Co, and Ni that quantitatively agree with existing ferromagnetic resonance measurements. This agreement establishes th...
0705.1990v1