General relativistic polytropes with a repulsive cosmological constant

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

General relativistic polytropes with a repulsive cosmological constant

Popis výsledku v původním jazyce

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 $lambda = rho_{vac}/rho_c ∼ 10^{-9}$.

Název v anglickém jazyce

General relativistic polytropes with a repulsive cosmological constant

Popis výsledku anglicky

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 $lambda = rho_{vac}/rho_c ∼ 10^{-9}$.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BN - Astronomie a nebeská mechanika, astrofyzika

OECD FORD obor

—

Projekt

<a href="/cs/project/GB14-37086G" target="_blank" >GB14-37086G: Centrum Alberta Einsteina pro gravitaci a astrofyziku</a><br>

Návaznosti

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

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název periodika

Physical Review D

ISSN

2470-0010

e-ISSN

—

Svazek periodika

94

Číslo periodika v rámci svazku

10

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

37

Strana od-do

'103513-1'-'103513-37'

Kód UT WoS článku

000394505600003

EID výsledku v databázi Scopus

2-s2.0-84995469163