General relativistic polytropes with a repulsive cosmological constant

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F47813059%3A19240%2F16%3AN0000028" target="_blank" >RIV/47813059:19240/16:N0000028 - isvavai.cz</a>

Result on the web

<a href="http://journals.aps.org/prd/abstract/10.1103/PhysRevD.94.103513" target="_blank" >http://journals.aps.org/prd/abstract/10.1103/PhysRevD.94.103513</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevD.94.103513" target="_blank" >10.1103/PhysRevD.94.103513</a>

Result language

angličtina

Original language name

General relativistic polytropes with a repulsive cosmological constant

Original language description

Spherically symmetric equilibrium configurations of perfect fluid obeying a polytropic equation of state are studied in spacetimes with a repulsive cosmological constant. The configurations are specified in terms of three parameters - the polytropic index $n$, the ratio of central pressure and central energy density of matter $sigma$, and the ratio of energy density of vacuum and central density of matter $lambda$. The static equilibrium configurations are determined by two coupled first-order nonlinear differential equations that are solved by numerical methods with the exception of polytropes with $n = 0$ corresponding to the configurations with a uniform distribution of energy density, when the solution is given in terms of elementary functions. The geometry of the polytropes is conveniently represented by embedding diagrams of both the ordinary space geometry and the optical reference geometry reflecting some dynamical properties of the geodesic motion. The polytropes are represented by radial profiles of energy density, pressure, mass, and metric coefficients. For all tested values of $n > 0$, the static equilibrium configurations with fixed parameters $n$, $sigma$, are allowed only up to a critical value of the cosmological parameter $lamda_c = lambda_c (n, σ)$. In the case of $n > 3$, the critical value $lambda_c$ tends to zero for special values of $sigma$. The gravitational potential energy and the binding energy of the polytropes are determined and studied by numerical methods. We discuss in detail the polytropes with an extension comparable to those of the dark matter halos related to galaxies, i.e., with extension $l >100 kpc$ and mass $M > 10^{12} M_{circle dot}$. For such largely extended polytropes, the cosmological parameter relating the vacuum energy to the central density has to be larger than $lambda = rho_{vac}/rho_c ∼ 10^{-9}$.

Czech name

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Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

BN - Astronomy and celestial mechanics, astrophysics

OECD FORD branch

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Project

<a href="/en/project/GB14-37086G" target="_blank" >GB14-37086G: Albert Einstein Center for Gravitation and Astrophysics</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2016

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Physical Review D

ISSN

2470-0010

e-ISSN

—

Volume of the periodical

94

Issue of the periodical within the volume

10

Country of publishing house

US - UNITED STATES

Number of pages

37

Pages from-to

'103513-1'-'103513-37'

UT code for WoS article

000394505600003

EID of the result in the Scopus database

2-s2.0-84995469163