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Related papers: Radiative Bulk Viscosity

200 papers

We consider an effective viscous pressure as the result of a backreaction of inhomogeneities within Buchert's formalism. The use of an effective metric with a time-dependent curvature radius allows us to calculate the luminosity distance of…

General Relativity and Quantum Cosmology · Physics 2016-04-13 Rodrigo M. Barbosa , G. Eddy , I. Chirinos , Winfried Zimdahl , Oliver F. Piattella

A new model is proposed to a collapsing star consisting of an anisotropic fluid with bulk viscosity, radial heat flow and outgoing radiation. In a previous paper one of us has introduced a function time dependent into the $g_{rr}$, besides…

General Relativity and Quantum Cosmology · Physics 2013-01-14 G. Pinheiro , R. Chan

The Rossby mode (r-mode) perturbation in pulsars as a steady gravitational wave (GW) source has been explored. The effect of a rigid crust on viscous damping and dissipation rate in the boundary layer between fluid core and crust has been…

Nuclear Theory · Physics 2025-02-24 Debasis Atta , D. N. Basu

We compute first and second-order bulk-viscous transport properties due to weak-interaction processes in $npe$ matter in the neutrino transparent regime. The transport coefficients characterize the out-of-beta-equilibrium pressure…

Nuclear Theory · Physics 2023-12-18 Yumu Yang , Mauricio Hippert , Enrico Speranza , Jorge Noronha

The standard thin accretion disk model has been successfully used to explain the soft X-ray spectra of Galactic black hole systems and perhaps the UV emission of Active Galactic Nuclei. However, radiation pressure dominated disks are known…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Agnieszka Janiuk , Ranjeev Misra

The kinetic energy of bulk relativistic plasma ejected from the central engine of blazars is converted into nonthermal particle energy in the comoving frame through a process of sweeping up material from the surrounding medium. The…

Astrophysics · Physics 2009-10-31 Charles D. Dermer

Exact solutions for a model with variable $G$, $\Lambda$ and bulk viscosity are obtained. Inflationary solutions with constant (de Sitter-type) and variable energy density are found. An expanding anisotropic universe is found to isotropize…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Arbab I. Arbab

In the present work, we explore the Rossby mode instabilities in neutron stars as sources of gravitational waves. The intensity and time evolution of the emitted gravitational waves in terms of the amplitude of the strain tensor are…

Data on stopping in intermediate-energy central heavy-ion collisions are analyzed following transport theory based on the Boltzmann equation. In consequence, values of nuclear shear viscosity are inferred. The inferred values are…

Nuclear Theory · Physics 2009-06-12 P. Danielewicz , B. Barker , L. Shi

We concentrate on calculation of the shear and bulk viscosities of the hadron gas. They define its dissipative dynamics and influence its experimentally measurable elliptic flow. Due to difficulty of this calculation the relaxation time…

High Energy Physics - Phenomenology · Physics 2016-01-01 O. Moroz

Active particles with a temperature distribution, "hot particles", have a distinct effect on the fluid that surrounds them. The temperature gradients they create deem the fluid's viscosity spatially dependent, therefore violating the…

Soft Condensed Matter · Physics 2024-08-27 Osher Arbib , Naomi Oppenheimer

The viscosity of liquids under nanoconfinement remains controversial. Reports range from spontaneous solidification to no change in the viscosity at all. Here, we present thorough measurements with a small-amplitude linear atomic force…

Soft Condensed Matter · Physics 2012-10-15 Shah H. Khan , Peter M. Hoffmann

We analyze gravitational waves propagating in an isotropic cosmic fluid endowed with a bulk viscosity $\zeta$ and a shear viscosity $\eta$, assuming these coefficients to vary with fluid density $\rho$ as $\rho^\lambda$, with $\lambda=1/2$…

General Relativity and Quantum Cosmology · Physics 2019-07-16 Iver Brevik , Shin'ichi Nojiri

We analyze the effects induced by the bulk viscosity on the dynamics associated to the extreme gravitational collapse. Aim of the work is to investigate whether the presence of viscous corrections to the evolution of a collapsing gas cloud…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Nakia Carlevaro , Giovanni Montani

We investigate the effect of antikaon condensed matter on bulk viscosity in rotating neutron stars. We use relativistic field theoretical models to construct the equation of state of neutron stars with the condensate, where the phase…

Astrophysics · Physics 2007-12-31 Debarati Chatterjee , Debades Bandyopadhyay

In this work, we have studied, for the first time, the impact of a realistic picture of a time dependent electric and magnetic field on the shear and bulk viscosities of the medium. Both the electric and magnetic fields are considered to be…

High Energy Physics - Phenomenology · Physics 2025-05-15 Debarshi Dey , Gowthama K K , Sadhana Dash , Basanta Kumar Nandi

We estimate the shear and the bulk viscous coefficients for a hot hadronic gas mixture constituting of pions and nucleons. The viscosities are evaluated in the relativistic kinetic theory approach by solving the transport equation in the…

Nuclear Theory · Physics 2017-03-13 Utsab Gangopadhyaya , Snigdha Ghosh , Sukanya Mitra , Sourav Sarkar

We study the effects of the shear and bulk viscosities in the hadronic phase on the expansion of the fireball and on the particle production in relativistic heavy ion collisions. Comparing simulation with or without viscosity in the…

Nuclear Theory · Physics 2010-04-14 Piotr Bozek

Kubo's formula relates bulk viscosity to the retarded Green's function of the trace of the energy-momentum tensor. Using low energy theorems of QCD for the latter we derive the formula which relates the bulk viscosity to the energy density…

High Energy Physics - Phenomenology · Physics 2008-11-26 D. Kharzeev , K. Tuchin

State-of-the-art fluid dynamical simulations of relativistic heavy-ion collisions employ initial state models which result in a rather strong radial flow. In order to fit the experimental observables, a non-negligible bulk viscosity of the…

Nuclear Theory · Physics 2022-05-12 Josef Bobek , Iurii Karpenko