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Related papers: Viscosity to entropy density ratio: violation of t…

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In this work, we introduce a notion of reachability entropy to characterize the smallest data rate which is sufficient enough to enforce reach-while-stay specification. We also define data rates of coder-controllers that can enforce this…

Optimization and Control · Mathematics 2022-06-22 Mahendra Singh Tomar , Majid Zamani

Extending our previous work, we study the relative entropy between the reduced density matrices obtained from globally excited states in conformal field theories of arbitrary dimensions. We find a general formula in the small subsystem size…

High Energy Physics - Theory · Physics 2017-03-08 Gábor Sárosi , Tomonori Ugajin

We calculate shear viscosity to entropy density ratio in presence of four derivative (with coefficient $\alpha'$) and six derivative (with coefficient $\alpha'^2$) terms in bulk action. In general, there can be three possible four…

High Energy Physics - Theory · Physics 2009-07-22 Nabamita Banerjee , Suvankar Dutta

Casimir entropies due to quantum fluctuations in the interaction between electrical bodies can often be negative, either caused by dissipation or by geometry. Although generally such entropies vanish at zero temperature, consistent with the…

High Energy Physics - Theory · Physics 2016-10-19 Yang Li , K. A. Milton , Pushpa Kalauni , Prachi Parashar

We examine the effects of higher derivative corrections on eta/s, the ratio of shear viscosity to entropy density, in the case of a finite R-charge chemical potential. In particular, we work in the framework of five-dimensional N =2 gauged…

High Energy Physics - Theory · Physics 2009-09-02 Sera Cremonini , Kentaro Hanaki , James T. Liu , Phillip Szepietowski

We calculate the shear (eta) and bulk (zeta) viscosities of a weakly coupled quark gluon plasma at the leading-log order with finite temperature T and quark chemical potential mu. We find that the shear viscosity to entropy density ratio…

High Energy Physics - Phenomenology · Physics 2013-05-30 Jiunn-Wei Chen , Yen-Fu Liu , Yu-Kun Song , Qun Wang

We investigate QCD matter using the two-flavor PNJL model and find that the shear viscosity to entropy density ratio {\eta}/s reaches a minimum while the bulk viscosity {\zeta}/s peaks near the chiral crossover line, particularly at large…

General Physics · Physics 2025-04-29 Jingxu Wu , Yuwei Yin , Jianing Shi

We study the influence of a temperature-dependent shear viscosity over entropy density ratio $\eta/s$, different shear relaxation times $\tau_\pi$, as well as different initial conditions on the transverse momentum spectra of charged…

Nuclear Theory · Physics 2013-05-30 H. Niemi , G. S. Denicol , P. Huovinen , E. Molnár , D. H. Rischke

We present, for the first time, simultaneous determination of shear viscosity ($\eta$) and entropy density ($s$) and thus, $\eta/s$ for equilibrated nuclear systems from $A$ $\sim$ 30 to $A$ $\sim$ 208 at different temperatures. At finite…

The nonzero bulk viscosity signals breaking of the scale invariance. We demonstrate that a disorder in two-dimensional noninteracting electron gas in a perpendicular magnetic field results in the nonzero disorder-averaged bulk viscosity. We…

Mesoscale and Nanoscale Physics · Physics 2021-06-07 V. A. Zakharov , I. S. Burmistrov

The concept of negative temperatures has occasionally been used in connection with quantum systems. A recent example of this sort is reported in the paper of S. Braun et al. [Science 339,52 (2013)], where an attractively interacting…

General Relativity and Quantum Cosmology · Physics 2013-10-01 Iver Brevik , Øyvind Grøn

In interaction-dominated two-dimensional electron gases at intermediate temperatures, electron transport is not diffusive as in the conventional Drude picture but instead hydrodynamic. The relevant transport coefficient in this regime is…

Mesoscale and Nanoscale Physics · Physics 2023-12-18 Ulf Gran , Eric Nilsson , Johannes Hofmann

The detailed fluctuation theorem (DFT) is a statement about the asymmetry in the statistics of the entropy production. Consequences of the DFT are the second law of thermodynamics and the thermodynamics uncertainty relation (TUR), which…

Statistical Mechanics · Physics 2022-10-19 Domingos S. P. Salazar

We describe recent attempts to extract the shear viscosity of the dilute Fermi gas at unitarity from experiments involving scaling flows. A scaling flow is a solution of the hydrodynamic equations that preserves the shape of the density…

Quantum Gases · Physics 2015-05-14 Thomas Schaefer , Clifford Chafin

The von Neumann entropy density of a block of n spins is proved to be non-zero for large n in the non-equilibrium steady state of the XY chain constructed by coupling a finite cutout of the chain to the two infinite parts to its left and…

Mathematical Physics · Physics 2007-05-23 Walter H. Aschbacher

We investigate two transport coefficients, shear viscosity and conductivity, in a non-relativistic boundary filed theory without hyperscaling symmetry, which is dual to a bulk charged hyperscaling violating black brane. Employing matching…

High Energy Physics - Theory · Physics 2017-09-13 Xiao-Mei Kuang , Jian-Pin Wu

We consider the Euler equations for compressible fluids in a nozzle whose cross-section is variable and may contain discontinuities. We view these equations as a hyperbolic system in nonconservative form and investigate weak solutions in…

Numerical Analysis · Mathematics 2008-12-24 Dietmar Kroener , Philippe G. LeFloch , Mai-Duc Thanh

A computation of the quotient of shear viscosity to entropy density, or KSS number $\eta/s$ is performed, in the non-relativistic and classical regime, first in Chiral Perturbation Theory, and then in the $SO(g+1)/SO(g)$ Non-Linear Sigma…

High Energy Physics - Theory · Physics 2008-11-26 Antonio Dobado , Felipe J. Llanes-Estrada

We calculate the transport coefficient of hadronic matter in the presence of temperature and magnetic field using the linear sigma model. In the relaxation time approximation, we estimate the shear viscosity over entropy density $\eta/s$.…

High Energy Physics - Phenomenology · Physics 2022-06-22 Ritesh Ghosh , Najmul Haque

We say that the vanishing viscosity limit holds in the classical sense if the velocity for a solution to the Navier-Stokes equations converges in the energy norm uniformly in time to the velocity for a solution to the Euler equations. We…

Mathematical Physics · Physics 2009-03-18 James P. Kelliher