Stable thin-shells from 5-dimensional extremal Einstein–Yang–Mills fields

2019 ◽  
Vol 16 (10) ◽  
pp. 1950148
Author(s):  
S. Habib Mazharimousavi ◽  
Mustafa Halilsoy
Keyword(s):  
Equation Of State ◽  
Speed Of Sound ◽  
Thin Shells ◽  
Barotropic Fluid ◽  
Yang Mills ◽  
State Formula ◽  
Generic Equation

By employing exact Einstein–Yang–Mills (EYM) solution in [Formula: see text] dimensions we establish spherical thin-shells with mass and Yang–Mills charge. Remarkably these shells are stable against linear, radial perturbations with a barotropic fluid presented on the shell with a generic equation of state [Formula: see text] supporting the speed of sound [Formula: see text].

scholarly journals Barotropic fluid compatible parametrizations of dark energy

2020 ◽  
Vol 80 (7) ◽  
Author(s):  
Dalibor Perković ◽  
Hrvoje Štefančić
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Speed Of Sound ◽  
Functional Form ◽  
State Parameter ◽  
Model Parameters ◽  
Barotropic Fluid ◽  
Energy Models ◽  
Equation Of State Parameter ◽  
Fundamental Requirement

Abstract Parametrizations of equation of state parameter as a function of the scale factor or redshift are frequently used in dark energy modeling. The question investigated in this paper is if parametrizations proposed in the literature are compatible with the dark energy being a barotropic fluid. The test of this compatibility is based on the functional form of the speed of sound squared, which for barotropic fluid dark energy follows directly from the function for the Equation of state parameter. The requirement that the speed of sound squared should be between 0 and speed of light squared provides constraints on model parameters using analytical and numerical methods. It is found that this fundamental requirement eliminates a large number of parametrizations as barotropic fluid dark energy models and puts strong constraints on parameters of other dark energy parametrizations.

Speed-of-Sound Measurements and a Fundamental Equation of State for Propylene Glycol

2021 ◽  
Vol 50 (2) ◽  
pp. 023105
Author(s):  
Tim Eisenbach ◽  
Christian Scholz ◽  
Roland Span ◽  
Diego Cristancho ◽  
Eric W. Lemmon ◽  
...  
Keyword(s):  
Equation Of State ◽  
Propylene Glycol ◽  
Speed Of Sound ◽  
Fundamental Equation ◽  
Fundamental Equation Of State

SHOCK WAVE COSMOLOGY INSIDE A BLACK HOLE: THE CASE OF NON-CRITICAL EXPANSION

2004 ◽  
Vol 01 (03) ◽  
pp. 429-443
Author(s):  
JOEL SMOLLER ◽  
BLAKE TEMPLE
Keyword(s):  
Shock Wave ◽  
Black Hole ◽  
Equation Of State ◽  
Closed System ◽  
Big Bang ◽  
Speed Of Light ◽  
State Formula ◽  
The Big Bang

We derive and analyze the equations that extend the results in [20,21] to the case of non-critical expansion k≠0. By an asymptotic argument we show that the equation of state [Formula: see text] plays the same distinguished role in the analysis when k≠0 as it does when k=0: only for this equation of state does the shock emerge from the Big Bang at a finite nonzero speed — the speed of light. We also obtain a simple closed system that extends the case [Formula: see text] considered in [20,21] to the case of a general positive, increasing, convex equation of state p=p(ρ).

Gravitational collapse of dust fluid and dark energy in the presence of curvature: Black hole formation

2019 ◽  
Vol 34 (29) ◽  
pp. 1950240 ◽  
Author(s):  
Syed Zaheer Abbas ◽  
Hasrat Hussain Shah ◽  
Huafei Sun ◽  
Farook Rahaman ◽  
Faizuddin Ahmed
Keyword(s):  
Black Hole ◽  
Dark Energy ◽  
Equation Of State ◽  
Gravitational Collapse ◽  
Dust Cloud ◽  
Curvature Effect ◽  
Hole Formation ◽  
Black Hole Formation ◽  
State Formula ◽  
Dust Fluid

Study of gravitational collapse and black hole formation has got much interest in recent years after gravitational waves detection from mergers of black hole binaries. Here, we studied the gravitational collapse of a spherically symmetric clump of matter, constituted of dust fluid, [Formula: see text], in a background of dark energy, [Formula: see text]. We investigate the curvature effect [Formula: see text] on the gravitational collapsing process. Gravitational collapsing process for two different cases is discussed i.e. collapse of dust cloud only and collapse of dark energy. We used equation of state [Formula: see text], [Formula: see text]. For dark energy case, we discuss the collapsing process and curvature effect for different parameter values of equation of state.

scholarly journals Impact of generalized polytropic equation of state on charged anisotropic polytropes

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
S. A. Mardan ◽  
M. Rehman ◽  
I. Noureen ◽  
R. N. Jamil
Keyword(s):  
Equation Of State ◽  
Speed Of Sound ◽  
Graphical Analysis ◽  
Maxwell Field ◽  
Anisotropic Fluid ◽  
Polytropic Index ◽  
Model Parameters ◽  
Field Equations ◽  
Polytropic Equation ◽  
Fluid Configuration

Abstract In this paper, generalized polytropic equation of state is used to get new classes of polytropic models from the solution of Einstein-Maxwell field equations for charged anisotropic fluid configuration. The models are developed for different values of polytropic index $$n=1,~\frac{1}{2},~2$$n=1,12,2. Masses and radii of eight different stars have been regained with the help of developed models. The speed of sound technique and graphical analysis of model parameters is used for the viability of developed models. The analysis of models indicates they are well behaved and physically viable.

scholarly journals The equation of state with non-equilibrium methods

2018 ◽  
Vol 175 ◽  
pp. 07028 ◽  
Author(s):  
Alessandro Nada ◽  
Michele Caselle ◽  
Marco Panero
Keyword(s):  
Monte Carlo ◽  
Equation Of State ◽  
Monte Carlo Simulations ◽  
Large Set ◽  
Yang Mills ◽  
Novel Technique ◽  
Lattice Gauge ◽  
Lattice Gauge Theories ◽  
Jarzynski’S Equality

Jarzynski’s equality provides an elegant and powerful tool to directly compute differences in free energy in Monte Carlo simulations and it can be readily extended to lattice gauge theories to compute a large set of physically interesting observables. In this talk we present a novel technique to determine the thermodynamics of stronglyinteracting matter based on this relation, which allows for a direct and efficient determination of the pressure using out-of-equilibrium Monte Carlo simulations on the lattice. We present results for the equation of state of the SU(3) Yang-Mills theory in the confined and deconfined phases. Finally, we briefly discuss the generalization of this method for theories with fermions, with particular focus on the equation of state of QCD.

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