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47
2019-12-13
Distance between Bound Entangled States from Unextendible Product Bases and Separable States
We discuss the use of the Gilbert algorithm to tailor entanglement witnesses for unextendibleproduct basis bound entangled states (UPB BE states). The method relies on the fact that an optimalentanglement witness is given by a plane perpendicular to a line between the reference state, entanglementof which is to be witn...
1912.06569v2
2020-10-16
Genome organization: experiments and modelling
This is an introduction to the special issue Genome organization: experiments and simulations, published in Chromosome Research, volume 25, issue 1 (2017).
2010.08464v1
2023-10-17
Sparse grid approximation of stochastic parabolic PDEs: The Landau--Lifshitz--Gilbert equation
We show convergence rates for a sparse grid approximation of the distribution of solutions of the stochastic Landau-Lifshitz-Gilbert equation. Beyond being a frequently studied equation in engineering and physics, the stochastic Landau-Lifshitz-Gilbert equation poses many interesting challenges that do not appear simul...
2310.11225v2
2024-04-04
Resolving Gilbert's Conjecture: Dimensional Dependencies in Hardy Spaces Valued in Clifford Modules
This article provides a thorough investigation into Gilbert's Conjecture, pertaining to Hardy spaces in the upper half-space valued in Clifford modules. We explore the conjecture proposed by Gilbert in 1991, which seeks to extend the classical principle of representing real $L^p$ functions on the real line as boundary ...
2404.03478v1
1998-02-23
Shell Effects on Rotational Damping in Superdeformed Nuclei
Damping of rotational motion in superdeformed Hg and Dy-region nuclei is studied by means of cranked shell model diagonalization. It is shown that a shell oscillation in single-particle alignments affects significantly properties of rotational damping. Onset properties of damping and damping width for Hg are quite diff...
9802065v1
2003-08-29
Influence of radiative damping on the optical-frequency susceptibility
Motivated by recent discussions concerning the manner in which damping appears in the electric polarizability, we show that (a) there is a dependence of the nonresonant contribution on the damping and that (b) the damping enters according to the "opposite sign prescription." We also discuss the related question of how ...
0309001v1
2024-03-19
Weakly elliptic damping gives sharp decay
We prove that weakly elliptic damping gives sharp energy decay for the abstract damped wave semigroup, where the damping is not in the functional calculus. In this case, there is no overdamping. We show applications in linearised water waves and Kelvin--Voigt damping.
2403.13067v1
2015-05-15
Reliable Damping of Free Surface Waves in Numerical Simulations
This paper generalizes existing approaches for free-surface wave damping via momentum sinks for flow simulations based on the Navier-Stokes equations. It is shown in 2D flow simulations that, to obtain reliable wave damping, the coefficients in the damping functions must be adjusted to the wave parameters. A scaling la...
1505.04087v2
2019-02-25
Resonant absorption as a damping mechanism for the transverse oscillations of the coronal loops observed by SDO/AIA
Solar coronal loops represent the variety of fast, intermediate, and slow normal mode oscillations. In this study, the transverse oscillations of the loops with a few-minutes period and also with damping caused by the resonant absorption were analyzed using extreme ultraviolet (EUV) images of the Sun. We employed the 1...
1902.09649v1
2013-05-21
Characterization and Synthesis of Rayleigh Damped Elastodynamic Networks
We consider damped elastodynamic networks where the damping matrix is assumed to be a non-negative linear combination of the stiffness and mass matrices (also known as Rayleigh or proportional damping). We give here a characterization of the frequency response of such networks. We also answer the synthesis question for...
1305.4961v1
2016-08-08
Damping Functions correct over-dissipation of the Smagorinsky Model
This paper studies the time-averaged energy dissipation rate $\langle \varepsilon_{SMD} (u)\rangle$ for the combination of the Smagorinsky model and damping function. The Smagorinsky model is well known to over-damp. One common correction is to include damping functions that reduce the effects of model viscosity near w...
1608.02655v2
2012-01-27
Full and Half Gilbert Tessellations with Rectangular Cells
We investigate the ray-length distributions for two different rectangular versions of Gilbert's tessellation. In the full rectangular version, lines extend either horizontally (with east- and west-growing rays) or vertically (north- and south-growing rays) from seed points which form a Poisson point process, each ray s...
1201.5780v1
2021-06-08
On numerical aspects of parameter identification for the Landau-Lifshitz-Gilbert equation in Magnetic Particle Imaging
The Landau-Lifshitz-Gilbert equation yields a mathematical model to describe the evolution of the magnetization of a magnetic material, particularly in response to an external applied magnetic field. It allows one to take into account various physical effects, such as the exchange within the magnetic material itself. I...
2106.07625v1
2000-09-11
Numerical Studies on Locally Damped Structures
In the JLC/NLC X-band linear collider, it is essential to reduce the long-range dipole wakefields in the accelerator structure to prevent beam break up (BBU) and emittance degradation. The two methods of reducing the long-range wakefields are detuning and damping. Detuning reduces the wakefields rapidly as the dipole m...
0009039v1
2015-03-13
A one-step optimal energy decay formula for indirectly nonlinearly damped hyperbolic systems coupled by velocities
In this paper, we consider the energy decay of a damped hyperbolic system of wave-wave type which is coupled through the velocities. We are interested in the asymptotic properties of the solutions of this system in the case of indirect nonlinear damping, i.e. when only one equation is directly damped by a nonlinear dam...
1503.04126v1
2015-08-21
Radiative damping in wave guide based FMR measured via analysis of perpendicular standing spin waves in sputtered Permalloy films
The damping $\alpha$ of the spinwave resonances in 75 nm, 120 nm, and 200nm -thick Permalloy films is measured via vector-network-analyzer ferromagnetic-resonance (VNA-FMR) in the out-of-plane geometry. Inductive coupling between the sample and the waveguide leads to an additional radiative damping term. The radiative ...
1508.05265v1
2022-09-28
Tunable nonlinear damping in parametric regime
Nonlinear damping plays a significant role in several area of physics and it is becoming increasingly important to understand its underlying mechanism. However, microscopic origin of nonlinear damping is still a debatable topic. Here, we probe and report nonlinear damping in a highly tunable MoS2 nano mechanical drum r...
2209.14120v1
2005-11-07
The Effects of Alfven Waves and Radiation Pressure in Dusty Winds of Late-Type Stars. II. Dust-Cyclotron Damping
There are in the literature several theories to explain the mass loss in stellar winds. In particular, for late-type stars, some authors have proposed a wind model driven by an outward-directed flux of damped Alfven waves. The winds of these stars present great amounts of dust particles that, if charged, can give rise ...
0511192v2
2013-09-11
Initial versus tangent stiffness-based Rayleigh damping in inelastic time history seismic analyses
In the inelastic time history analyses of structures in seismic motion, part of the seismic energy that is imparted to the structure is absorbed by the inelastic structural model, and Rayleigh damping is commonly used in practice as an additional energy dissipation source. It has been acknowledged that Rayleigh damping...
1309.2741v1
2017-07-14
Damping of gravitational waves by matter
We develop a unified description, via the Boltzmann equation, of damping of gravitational waves by matter, incorporating collisions. We identify two physically distinct damping mechanisms -- collisional and Landau damping. We first consider damping in flat spacetime, and then generalize the results to allow for cosmolo...
1707.05192v2
2024-03-13
The q-ary Gilbert-Varshamov bound can be improved for all but finitely many positive integers q
For any positive integer $q\geq 2$ and any real number $\delta\in(0,1)$, let $\alpha_q(n,\delta n)$ denote the maximum size of a subset of $\mathbb{Z}_q^n$ with minimum Hamming distance at least $\delta n$, where $\mathbb{Z}_q=\{0,1,\dotsc,q-1\}$ and $n\in\mathbb{N}$. The asymptotic rate function is defined by $ R_q(\d...
2403.08727v2
2002-06-27
Initial-amplitude dependence in weakly damped oscillators
A pedagogically instructive experimental procedure is suggested for distinguishing between different damping terms in a weakly damped oscillator, which highclights the connection between non-linear damping and initial-amplitude dependence. The most common damping terms such as contact friction, air resistance, viscous ...
0206086v1
2006-05-22
The entanglement of damped noon-state and its performance in phase measurement
The state evolution of the initial optical \textit{noon} state is investigated. The residue entanglement of the state is calculated after it is damped by amplitude and phase damping. The relative entropy of entanglement of the damped state is exactly obtained. The performance of direct application of the damped \textit...
0605184v1
2007-10-04
Channel-Adapted Quantum Error Correction for the Amplitude Damping Channel
We consider error correction procedures designed specifically for the amplitude damping channel. We analyze amplitude damping errors in the stabilizer formalism. This analysis allows a generalization of the [4,1] `approximate' amplitude damping code of quant-ph/9704002. We present this generalization as a class of [2(M...
0710.1052v1
2010-03-24
Dynamical shift condition for unequal mass black hole binaries
Certain numerical frameworks used for the evolution of binary black holes make use of a gamma driver, which includes a damping factor. Such simulations typically use a constant value for damping. However, it has been found that very specific values of the damping factor are needed for the calculation of unequal mass bi...
1003.4681v1
2011-11-30
Local phase damping of single qubits sets an upper bound on the phase damping rate of entangled states
I derive an inequality in which the phase damping rates of single qubits set an upper bound for the phase damping rate of entangled states of many qubits. The derivation is based on two assumptions: first, that the phase damping can be described by a dissipator in Lindblad form and, second, that the phase damping prese...
1111.7152v2
2012-05-11
Quantum dynamics of the damped harmonic oscillator
The quantum theory of the damped harmonic oscillator has been a subject of continual investigation since the 1930s. The obstacle to quantization created by the dissipation of energy is usually dealt with by including a discrete set of additional harmonic oscillators as a reservoir. But a discrete reservoir cannot direc...
1205.2545v1
2014-02-28
Escape rate for the power-law distribution in low-to-intermediate damping
Escape rate in the low-to-intermediate damping connecting the low damping with the intermediate damping is established for the power-law distribution on the basis of flux over population theory. We extend the escape rate in the low damping to the low-to-intermediate damping, and get an expression for the power-law dist...
1402.7194v2
2015-03-21
On damping created by heterogeneous yielding in the numerical analysis of nonlinear reinforced concrete frame elements
In the dynamic analysis of structural engineering systems, it is common practice to introduce damping models to reproduce experimentally observed features. These models, for instance Rayleigh damping, account for the damping sources in the system altogether and often lack physical basis. We report on an alternative pat...
1503.07122v1
2016-01-20
Introduction to Landau Damping
The mechanism of Landau damping is observed in various systems from plasma oscillations to accelerators. Despite its widespread use, some confusion has been created, partly because of the different mechanisms producing the damping but also due to the mathematical subtleties treating the effects. In this article the ori...
1601.05227v1
2018-07-25
Regularity and asymptotic behaviour for a damped plate-membrane transmission problem
We consider a transmission problem where a structurally damped plate equation is coupled with a damped or undamped wave equation by transmission conditions. We show that exponential stability holds in the damped-damped situation and polynomial stability (but no exponential stability) holds in the damped-undamped case. ...
1807.09730v1
2021-08-04
Nonlinear fluid damping of elastically mounted pitching wings in quiescent water
We experimentally study the nonlinear fluid damping of a rigid but elastically mounted pitching wing in the absence of a freestream flow. The dynamics of the elastic mount are simulated using a cyber-physical system. We perturb the wing and measure the fluid damping coefficient from damped oscillations over a large ran...
2108.02090v1
2002-11-03
Damping of coupled phonon--plasmon modes
The effect of free carriers on dispersion and damping of coupled phonon-plasmon modes is considered in the long-wave approximation. The electron and phonon scattering rate as well as Landau damping are taken into account.
0211040v1
2002-02-01
On "the authentic damping mechanism" of the phonon damping model
Some general features of the phonon damping model are presented. It is concluded that the fits performed within this model have no physical content.
0202006v1
2010-12-20
Global attractors for the one dimensional wave equation with displacement dependent damping
We study the long-time behavior of solutions of the one dimensional wave equation with nonlinear damping coefficient. We prove that if the damping coefficient function is strictly positive near the origin then this equation possesses a global attractor.
1012.4455v1
2018-01-28
Observations of excitation and damping of transversal oscillation in coronal loops by AIA/SDO
The excitation and damping of transversal coronal loop oscillations and quantitative relation between damping time, damping quality (damping time per period), oscillation amplitude, dissipation mechanism and the wake phenomena are investigated. The observed time series data with the \textit{Atmospheric Imaging Assembly...
1801.09217v1
1999-11-16
Probing supernovae ejecta by Halpha damping wings
It is predicted that H$\alpha$ emission line at the early nebular epoch of type II-P supernovae may display robust observational effects of damping wings. This is illustrated by Monte-Carlo simulations. The strength of damping wing effects may be used to constrain parameters of the line-emitting zone. An anomalous reds...
9911300v1
2009-01-23
Rheological Interpretation of Rayleigh Damping
Damping is defined through various terms such as energy loss per cycle (for cyclic tests), logarithmic decrement (for vibration tests), complex modulus, rise-time or spectrum ratio (for wave propagation analysis), etc. For numerical modeling purposes, another type of damping is frequently used : it is called Rayleigh d...
0901.3717v1
2009-05-20
Eigenvalue asymptotics, inverse problems and a trace formula for the linear damped wave equation
We determine the general form of the asymptotics for Dirichlet eigenvalues of the one-dimensional linear damped wave operator. As a consequence, we obtain that given a spectrum corresponding to a constant damping term this determines the damping term in a unique fashion. We also derive a trace formula for this problem.
0905.3242v1
2015-05-06
Remarks on the asymptotic behavior of the solution of an abstract damped wave equation
We study an abstract damped wave equation. We prove that the solution of the damped wave equation becomes closer to the solution of a heat type equation as time tend to infinity. As an application of our approach, we also study the asymptotic behavior of the damped wave equation in Euclidean space under the geometric c...
1505.01794v2
2017-01-18
Two types of spurious damping forces potentially modeled in numerical seismic nonlinear response history analysis
The purpose of this paper is to provide practitioners with further insight into spurious damping forces that can be generated in nonlinear seismic response history analyses (RHA). The term 'spurious' is used to refer to damping forces that are not present in an elastic system and appear as nonlinearities develop: such ...
1701.05092v1
2017-02-02
Exponential stability for a coupled system of damped-undamped plate equations
We consider the transmission problem for a coupled system of undamped and structurally damped plate equations in two sufficiently smooth and bounded subdomains. It is shown that, independently of the size of the damped part, the damping is strong enough to produce uniform exponential decay of the energy of the coupled ...
1702.00637v1
2017-09-11
Comparison of damping mechanisms for transverse waves in solar coronal loops
We present a method to assess the plausibility of alternative mechanisms to explain the damping of magnetohydrodynamic (MHD) transverse waves in solar coronal loops. The considered mechanisms are resonant absorption of kink waves in the Alfv\'en continuum, phase-mixing of Alfv\'en waves, and wave leakage. Our methods m...
1709.03347v1
2019-03-25
Distributed Inter-Area Oscillation Damping Control for Power Systems by Using Wind Generators and Load Aggregators
This paper investigates the potential of wind turbine generators (WTGs) and load aggregators (LAs) to provide supplementary damping control services for low frequency inter-area oscillations (LFOs) through the additional distributed damping control units (DCUs) proposed in their controllers. In order to provide a scala...
1903.10135v1
2019-08-19
Spectral determinant for the damped wave equation on an interval
We evaluate the spectral determinant for the damped wave equation on an interval of length $T$ with Dirichlet boundary conditions, proving that it does not depend on the damping. This is achieved by analysing the square of the damped wave operator using the general result by Burghelea, Friedlander, and Kappeler on the ...
1908.06862v1
2020-10-12
Decays rates for Kelvin-Voigt damped wave equations II: the geometric control condition
We study in this article decay rates for Kelvin-Voigt damped wave equations under a geometric control condition. We prove that when the damping coefficient is sufficiently smooth ($C^1$ vanishing nicely) we show that exponential decay follows from geometric control conditions (see~\cite{BuCh, Te12} for similar results ...
2010.05614v2
2020-12-05
On Periodical Damping Ratio of a Controlled Dynamical System with Parametric Resonances
This report provides an interpretation on the periodically varying damping ratio of a dynamical system with direct control of oscillation or vibration damping. The principal parametric resonance of the system and a new type of parametric resonance, named "zero-th order" parametric resonance, are investigated by using t...
2012.02932v1
2021-06-09
Grammage of cosmic rays in the proximity of supernova remnants embedded in a partially ionized medium
We investigate the damping of Alfv\'en waves generated by the cosmic ray resonant streaming instability in the context of the cosmic ray escape and propagation in the proximity of supernova remnants. We consider ion-neutral damping, turbulent damping and non linear Landau damping in the warm ionized and warm neutral ph...
2106.04948v1
2021-06-22
Sharp decay rate for the damped wave equation with convex-shaped damping
We revisit the damped wave equation on two-dimensional torus where the damped region does not satisfy the geometric control condition. We show that if the damping vanishes as a H\"older function $|x|^{\beta}$, and in addition, the boundary of the damped region is strictly convex, the wave is stable at rate $t^{-1+\frac...
2106.11782v3
2021-08-09
Effect of stepwise adjustment of Damping factor upon PageRank
The effect of adjusting damping factor {\alpha}, from a small initial value {\alpha}0 to the final desired {\alpha}f value, upon then iterations needed for PageRank computation is observed. Adjustment of the damping factor is done in one or more steps. Results show no improvement in performance over a fixed damping fac...
2108.04150v1
2021-08-17
Asymptotic behaviour of the wave equation with nonlocal weak damping, anti-damping and critical nonlinearity
In this paper we prove the existence of the global attractor for the wave equation with nonlocal weak damping, nonlocal anti-damping and critical nonlinearity.
2108.07395v2
2023-02-23
Buckling Metamaterials for Extreme Vibration Damping
Damping mechanical resonances is a formidable challenge in an increasing number of applications. Many of the passive damping methods rely on using low stiffness dissipative elements, complex mechanical structures or electrical systems, while active vibration damping systems typically add an additional layer of complexi...
2302.11968v1
1997-11-20
Symmetric matrices and quantum codes
This paper has been withdrawn since a Gilbert-Varshamov bound for general quantum codes has already appeared in Ekert and Macchiavello, Prys. Rev. Lett. 77, p. 2585, and a Gilbert-Varshamov bound for stabilizer codes connected with orthogonal geometry, or equivalently, with symmetric matrices as in this paper, has been...
9711026v2
1994-06-09
Black Holes from Blue Spectra
Blue primordial power spectra with a spectral index $n>1$ can lead to a significant production of primordial black holes in the very early Universe. The evaporation of these objects leads to a number of observational consequences and a model independent upper limit of $n \approx 1.4$. In some cases this limit is streng...
9406028v1
1995-06-14
Inversions in astronomy and the SOLA method
This paper was presented at the Institute for Mathematics and its Applications workshop "Inverse problems in wave propagation" and will appear in the series IMA volumes (Springer). A brief overview of applications of inversions within astronomy is presented and also an inventory of techniques commonly in use. Most of t...
9506084v1
1997-11-11
No Need for MACHOS in the Halo
A simple interpretation of the more than dozen microlensing events seen in the direction of the LMC is a halo population of MACHOs which accounts for about half of the mass of the Galaxy. Such an interpretation is not without its problems, and we show that current microlensing data can, with some advantage, be explaine...
9711110v1
2006-02-11
Likelihood Functions for Galaxy Cluster Surveys
Galaxy cluster surveys offer great promise for measuring cosmological parameters, but survey analysis methods have not been widely studied. Using methods developed decades ago for galaxy clustering studies, it is shown that nearly exact likelihood functions can be written down for galaxy cluster surveys. The sparse sam...
0602251v3
2000-03-25
Thermokinetic approach of the generalized Landau-Lifshitz-Gilbert equation with spin polarized current
In order to describe the recently observed effect of current induced magnetization reversal in magnetic nanostructures, the thermokinetic theory is applied to a metallic ferromagnet in contact with a reservoir of spin polarized conduction electrons. The spin flip relaxation of the conduction electrons is described ther...
0003409v1
2004-05-26
Nonequilibrium Extension of the Landau-Lifshitz-Gilbert Equation for Magnetic Systems
Using the invariant operator method for an effective Hamiltonian including the radiation-spin interaction, we describe the quantum theory for magnetization dynamics when the spin system evolves nonadiabatically and out of equilibrium, $d \hat{\rho}/dt \neq 0$. It is shown that the vector parameter of the invariant oper...
0405599v1
2006-10-16
Properties of Codes with the Rank Metric
In this paper, we study properties of rank metric codes in general and maximum rank distance (MRD) codes in particular. For codes with the rank metric, we first establish Gilbert and sphere-packing bounds, and then obtain the asymptotic forms of these two bounds and the Singleton bound. Based on the asymptotic bounds, ...
0610099v2
1994-08-26
On the Dirichlet problem for harmonic maps with prescribed singularities
Let $\M$ be a classical Riemannian globally symmetric space of rank one and non-compact type. We prove the existence and uniqueness of solutions to the Dirichlet problem for harmonic maps into $\M$ with prescribed singularities along a closed submanifold of the domain. This generalizes our previous work where such maps...
9408005v1
1997-08-15
One-Loop Minimization Conditions in the Minimal Supersymmetric Standard Model
We study, in the Minimal Supersymmetric Standard Model, the electroweak symmetry breaking conditions obtained from the one-loop effective potential. Novel model-independent lower and upper bounds on $\tan \beta$, involving the other free parameters of the model, are inferred and determined analytically. We discuss brie...
9708368v1
2004-05-31
On a Penrose Inequality with Charge
We construct a time-symmetric asymptotically flat initial data set to the Einstein-Maxwell Equations which satisfies the inequality: m - 1/2(R + Q^2/R) < 0, where m is the total mass, R=sqrt(A/4) is the area radius of the outermost horizon and Q is the total charge. This yields a counter-example to a natural extension ...
0405602v3
2004-07-26
Automorphisms of free groups have asymptotically periodic dynamics
We show that every automorphism $\alpha$ of a free group $F_k$ of finite rank $k$ has {\it asymptotically periodic} dynamics on $F_k$ and its boundary $\partial F_k$: there exists a positive power $\alpha^q$ such that every element of the compactum $F_k \cup \partial F_k$ converges to a fixed point under iteration of $...
0407437v2
2004-12-30
The Construction of a Partially Regular Solution to the Landau-Lifshitz-Gilbert Equation in $\mathbb{R}^2$
We establish a framework to construct a global solution in the space of finite energy to a general form of the Landau-Lifshitz-Gilbert equation in $\mathbb{R}^2$. Our characterization yields a partially regular solution, smooth away from a 2-dimensional locally finite Hausdorff measure set. This construction relies on ...
0412534v1
2002-01-13
Inverse Cascade Regime in Shell Models of 2-Dimensional Turbulence
We consider shell models that display an inverse energy cascade similar to 2-dimensional turbulence (together with a direct cascade of an enstrophy-like invariant). Previous attempts to construct such models ended negatively, stating that shell models give rise to a "quasi-equilibrium" situation with equipartition of t...
0201020v1
2002-04-23
Algebraic decay in hierarchical graphs
We study the algebraic decay of the survival probability in open hierarchical graphs. We present a model of a persistent random walk on a hierarchical graph and study the spectral properties of the Frobenius-Perron operator. Using a perturbative scheme, we derive the exponent of the classical algebraic decay in terms o...
0204056v1
2004-03-11
Statistics of active vs. passive advections in magnetohydrodynamic turbulence
Active turbulent advection is considered in the context of magneto-hydrodynamics. In this case, an auxiliary passive field bears no apparent connection to the active field. The scaling properties of the two fields are different. In the framework of a shell model, we show that the two-point structure function of the pas...
0403017v1
2006-01-19
Drift of particles in self-similar systems and its Liouvillian interpretation
We study the dynamics of classical particles in different classes of spatially extended self-similar systems, consisting of (i) a self-similar Lorentz billiard channel, (ii) a self-similar graph, and (iii) a master equation. In all three systems the particles typically drift at constant velocity and spread ballisticall...
0601042v1
1997-11-20
Quantum self-dual codes and symmetric matrices
This paper has been withdrawn since a Gilbert-Varshamov bound for general quantum codes has already appeared in Ekert and Macchiavello, Prys. Rev. Lett. 77, p. 2585, and a Gilbert-Varshamov bound for stabilizer codes connected with orthogonal geometry, or equivalently, with symmetric matrices as in this paper, has been...
9711047v2
2001-06-06
Constraints on Eavesdropping on the BB84 Protocol
An undetected eavesdropping attack must produce count rate statistics that are indistinguishable from those that would arise in the absence of such an attack. In principle this constraint should force a reduction in the amount of information available to the eavesdropper. In this paper we illustrate, by considering a p...
0106034v2
2007-09-14
A complete proof of The Graceful Tree Conjecture using the concept of Edge Degree
We show the Graceful Tree Conjecture holds.
0709.2201v9
2007-09-24
An extension of a result concerning convex geometric graphs
We show a general result known as the Erdos_Sos Conjecture: if $E(G)>{1/2}(k-1)n$ where $G$ has order $n$ then $G$ contains every tree of order $k+1$ as a subgraph.
0709.3590v5
2008-06-13
Heat conduction and Fourier's law by consecutive local mixing and thermalization
We present a first-principles study of heat conduction in a class of models which exhibit a new multi-step local thermalization mechanism which gives rise to Fourier's law. Local thermalization in our models occurs as the result of binary collisions among locally confined gas particles. We explore the conditions under ...
0806.2193v1
2009-08-05
Persistence effects in deterministic diffusion
In systems which exhibit deterministic diffusion, the gross parameter dependence of the diffusion coefficient can often be understood in terms of random walk models. Provided the decay of correlations is fast enough, one can ignore memory effects and approximate the diffusion coefficient according to dimensional argume...
0908.0600v1
2009-08-10
Diffusion coefficients for multi-step persistent random walks on lattices
We calculate the diffusion coefficients of persistent random walks on lattices, where the direction of a walker at a given step depends on the memory of a certain number of previous steps. In particular, we describe a simple method which enables us to obtain explicit expressions for the diffusion coefficients of walks ...
0908.1271v1
2010-04-09
Strict inequalities of critical probabilities on Gilbert's continuum percolation graph
Any infinite graph has site and bond percolation critical probabilities satisfying $p_c^{site}\geq p_c^{bond}$. The strict version of this inequality holds for many, but not all, infinite graphs. In this paper, the class of graphs for which the strict inequality holds is extended to a continuum percolation model. In ...
1004.1596v2
2010-04-15
Rank of mapping tori and companion matrices
Given $f$ in $GL(d,Z)$, it is decidable whether its mapping torus (the semi-direct product of $Z^d$ with $Z$) may be generated by two elements or not; if so, one can classify generating pairs up to Nielsen equivalence. If $f$ has infinite order, the mapping torus of $f^n$ cannot be generated by two elements for $n$ lar...
1004.2649v1
2010-04-30
Limit theory for planar Gilbert tessellations
A Gilbert tessellation arises by letting linear segments (cracks) in the plane unfold in time with constant speed, starting from a homogeneous Poisson point process of germs in randomly chosen directions. Whenever a growing edge hits an already existing one, it stops growing in this direction. The resulting process tes...
1005.0023v1
2010-06-24
Periodic solutions for the Landau-Lifshitz-Gilbert equation
Ferromagnetic materials tend to develop very complex magnetization patterns whose time evolution is modeled by the so-called Landau-Lifshitz-Gilbert equation (LLG). In this paper, we construct time-periodic solutions for LLG in the regime of soft and small ferromagnetic particles which satisfy a certain shape condition...
1006.4765v1
2010-12-19
A counterexample to a Penrose inequality conjectured by Gibbons
We show that the Brill-Lindquist initial data provides a counterexample to a Riemannian Penrose inequality with charge conjectured by G. Gibbons. The observation illustrates a sub-additive characteristic of the area radii for the individual connected components of an outermost horizon as a lower bound of the ADM mass.
1012.4190v2
2011-11-27
A two-stage approach to relaxation in billiard systems of locally confined hard spheres
We consider the three-dimensional dynamics of systems of many interacting hard spheres, each individually confined to a dispersive environment, and show that the macroscopic limit of such systems is characterized by a coefficient of heat conduction whose value reduces to a dimensional formula in the limit of vanishingl...
1111.6272v1
2012-01-12
Coil-helix transition in poly(L-glutamic acid) : Evidence for a 3-state non-cooperative process
A careful analysis of measurements of circular dichroism of poly(L-glutamic acid) (PGA) shows that the data can be very accurately described by introducing a third state for the PGA configuration, in addition to the helix and coil ones, and considering a simple equilibrium between these three states, without cooperativ...
1201.2566v1
2012-03-20
Vortex dynamics in the presence of excess energy for the Landau-Lifschitz-Gilbert equation
We study the Landau-Lifshitz-Gilbert equation for the dynamics of a magnetic vortex system. We present a PDE-based method for proving vortex dynamics that does not rely on strong well-preparedness of the initial data and allows for instantaneous changes in the strength of the gyrovector force due to bubbling events. Th...
1203.4426v1
2012-12-22
Cumulative Distance Enumerators of Random Codes and their Thresholds
Cumulative weight enumerators of random linear codes are introduced, their asymptotic properties are studied, and very sharp thresholds are exhibited; as a consequence, it is shown that the asymptotic Gilbert-Varshamov bound is a very sharp threshold point for the density of the linear codes whose relative distance is ...
1212.5679v1
2013-01-23
The Importance of Continuous Value Based Project Management in the Context of Requirements Engineering
Despite several scientific achievements in the last years, there are still a lot of IT projects that fail. Researchers found that one out of five IT-projects run out of time, budget or value. Major reasons for this failure are unexpected economic risk factors that emerge during the runtime of projects. In order to be a...
1301.5438v1
2013-04-08
On Automorphisms and Subtowers of an asymptotically optimal Tower of Function Fields
In this article we investigate the automorphism group of an asymptotically optimal tower of function fields introduced by Garcia and Stichtenoth. In particular we provide a detailed description of the decomposition group of some rational places. This group acts on the algebraic-geometric standard codes obtained by the ...
1304.2145v1
2013-05-06
The Moment Generating function for ray lengths in the Half Gilbert Model with Rectangular Cells
In the full rectangular version of Gilbert's tessellation lines extend either horizontally (with east- and west--growing rays) or vertically (north- and south--growing rays) from seed points which form a Poisson point process, each ray stopping when another ray is met. In the half rectangular version, east and south gr...
1305.1289v1
2013-07-15
Degenerate transition pathways for screw dislocations: implications for migration
In body-centred-cubic (bcc) metals migrating 1/2<111> screw dislocations experience a periodic energy landscape with a triangular symmetry. Atomistic simulations, such as those performed using the nudged-elastic-band (NEB) method, generally predict a transition-pathway energy-barrier with a double-hump; contradicting A...
1307.3848v2
2013-08-17
The Riemannian Penrose Inequality with Charge for Multiple Black Holes
We present a proof of the Riemannian Penrose inequality with charge $r\leq m + \sqrt{m^2-q^2}$, where $A=4\pi r^2$ is the area of the outermost apparent horizon with possibly multiple connected components, $m$ is the total ADM mass, and $q$ the total charge of a strongly asymptotically flat initial data set for the Ein...
1308.3771v3
2013-08-23
Quotients and subgroups of Baumslag-Solitar groups
We determine all generalized Baumslag-Solitar groups (finitely generated groups acting on a tree with all stabilizers infinite cyclic) which are quotients of a given Baumslag-Solitar group BS(m,n), and (when BS(m,n) is not Hopfian) which of them also admit BS(m,n) as a quotient. We determine for which values of r,s one...
1308.5122v2
2013-12-17
Limit theory for the Gilbert graph
For a given homogeneous Poisson point process in $\mathbb{R}^d$ two points are connected by an edge if their distance is bounded by a prescribed distance parameter. The behaviour of the resulting random graph, the Gilbert graph or random geometric graph, is investigated as the intensity of the Poisson point process is ...
1312.4861v2
2014-03-13
Fibrations of ordered groupoids and the factorization of ordered functors
We investigate canonical factorizations of ordered functors of ordered groupoids through star-surjective functors. Our main construction is a quotient ordered groupoid, depending on an ordered version of the notion of normal subgroupoid, that results is the factorization of an ordered functor as a star-surjective funct...
1403.3254v2
2014-03-16
Interpolating local constants in families
We extend the theory of local constants to l-adic families of representations of GL_n(F) where F is a p-adic field with l not equal to p. We construct zeta integrals and gamma factors for representations coming from the conjectural "local Langlands correspondence in families" of Emerton-Helm, proving a rationality resu...
1403.3914v2
2014-06-10
A thin-film limit in the Landau-Lifshitz-Gilbert equation relevant for the formation of Néel walls
We consider an asymptotic regime for two-dimensional ferromagnetic films that is consistent with the formation of transition layers (N\'eel walls). We first establish compactness of S2-valued magnetizations in the energetic regime of N\'eel walls and characterize the set of accumulation points. We then prove that N\'ee...
1406.2709v1
2014-08-02
Machta-Zwanzig regime of anomalous diffusion in infinite-horizon billiards
We study diffusion on a periodic billiard table with infinite horizon in the limit of narrow corridors. An effective trapping mechanism emerges according to which the process can be modeled by a L\'evy walk combining exponentially-distributed trapping times with free propagation along paths whose precise probabilities ...
1408.0349v1
2014-12-11
Gamma factors of pairs and a local converse theorem in families
We prove a GL(n)xGL(n-1) local converse theorem for l-adic families of smooth representations of GL(n,F) where F is a finite extension of Q_p and l is different from p. To do so, we also extend the theory of Rankin-Selberg integrals, first introduced by Jacquet, Piatetski-Shapiro, and Shalika, to the setting of familie...
1412.3500v2
2015-05-28
A Geometric Interpretation of the Boolean Gilbert-Johnson-Keerthi Algorithm
The Gilbert-Johnson-Keerthi (GJK) algorithm is an iterative improvement technique for finding the minimum distance between two convex objects. It can easily be extended to work with concave objects and return the pair of closest points. [4] The key operation of GJK is testing whether a Voronoi region of a simplex conta...
1505.07873v1
2016-01-29
Ordered groupoid quotients and congruences on inverse semigroups
We introduce a preorder on an inverse semigroup $S$ associated to any normal inverse subsemigroup $N$, that lies between the natural partial order and Green's ${\mathscr J}$-relation. The corresponding equivalence relation $\simeq_N$ is not necessarily a congruence on $S$, but the quotient set does inherit a natural or...
1601.08194v1
2016-08-16
Closed inverse subsemigroups of graph inverse semigroups
As part of his study of representations of the polycylic monoids, M.V. Lawson described all the closed inverse submonoids of a polycyclic monoid $P_n$ and classified them up to conjugacy. We show that Lawson's description can be extended to closed inverse subsemigroups of graph inverse semigroups. We then apply B. Sche...
1608.04538v1