Dynamics of viscous dissipative collapse with casual approach in string inspired Gauss–Bonnet gravity

2019 ◽  
Vol 34 (10) ◽  
pp. 1950074
Author(s):  
M. Tahir ◽  
G. Abbas
Keyword(s):  
Heat Flux ◽  
Gravitational Collapse ◽  
Bulk Viscosity ◽  
Transport Equations ◽  
Coupling Coefficients ◽  
Dynamical Equations ◽  
Bonnet Gravity ◽  
Viscous Heat ◽  
Theory Of Gravity

In this work, we have studied the effects of dissipative viscous/heat gravitational collapse on the dynamics of collapsing source in 5D Einstein–Gauss–Bonnet theory using full casual approach. For this purpose, the dynamical equations have been formulated by using Misner–Sharp approach in 5D Einstein–Gauss–Bonnet theory of gravity. Using the Müller–Israel–Stewart theory, the dynamical equations have coupled with casual transport equations for the heat flux, the bulk and shear bulk viscosity to determine the effects of heat flux including thermodynamics viscous/heat coupling coefficients. The applications of this work to certain astrophysical situations are discussed.

scholarly journals DYNAMICS OF VISCOUS DISSIPATIVE GRAVITATIONAL COLLAPSE: A FULL CAUSAL APPROACH

2009 ◽  
Vol 18 (01) ◽  
pp. 129-145 ◽  
Author(s):  
L. HERRERA ◽  
A. DI PRISCO ◽  
E. FUENMAYOR ◽  
O. TROCONIS
Keyword(s):  
Heat Flux ◽  
Gravitational Collapse ◽  
Bulk Viscosity ◽  
Dynamical Equation ◽  
Transport Equations ◽  
Coupling Coefficients ◽  
Diffusion Approximations ◽  
Viscous Heat ◽  
Dissipative Case ◽  
Causal Approach

The Misner and Sharp approach to the study of gravitational collapse is extended to the viscous dissipative case in both the streaming out and the diffusion approximations. The dynamical equation is then coupled to causal transport equations for the heat flux, the shear, and the bulk viscosity, in the context of Israel–Stewart theory, without excluding the thermodynamics viscous/heat coupling coefficients. The result is compared with previous works where these later coefficients were neglected and viscosity variables were not assumed to satisfy causal transport equations. Prospective applications of this result to some astrophysical scenarios are discussed.

scholarly journals A Study of Charged Cylindrical Gravitational Collapse with Dissipative Fluid

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Sanjukta Chakraborty ◽  
Subenoy Chakraborty
Keyword(s):  
Heat Flux ◽  
Transport Equation ◽  
Gravitational Collapse ◽  
Thermodynamic Theory ◽  
Anisotropic Fluid ◽  
Heat Conducting ◽  
Dynamical Equations ◽  
Viscous Heat ◽  
Dissipative Fluid ◽  
Cylindrical Collapse

The present works deals with gravitational collapse of cylindrical viscous heat conducting anisotropic fluid following the work of Misner and Sharp. Using Darmois matching conditions, the dynamical equations are derived and the effects of charge and dissipative quantities over the cylindrical collapse are analyzed. Finally, using the Miller-Israel-Steward causal thermodynamic theory, the transport equation for heat flux is derived and its influence on collapsing system has been studied.

Dynamics of dissipative self-gravitating source in Rastall gravity

2021 ◽  
pp. 2150153
Author(s):  
M. Tahir ◽  
G. Abbas ◽  
Kazuharu Bamba ◽  
M. R. Shahzad
Keyword(s):  
Heat Flux ◽  
Transport Equation ◽  
Heat Transport ◽  
Gravitational Collapse ◽  
Diffusion Approximation ◽  
Field Equations ◽  
Dynamical Equations ◽  
Stewart Approach ◽  
Heat Transport Equation ◽  
And Diffusion

The dynamics of dissipative gravitational collapse of a source is explored in Rastall gravity. The field equations are derived for the geometry and collapsing matter. The dynamical equations are formulated for the heat flux and diffusion approximation. The heat transportation equation is derived by using Müller–Israel–Stewart approach to investigate the effects of heat flux on the collapsing source. Moreover, an equation is found by combining the dynamical and heat transport equation, the consequences of this equation are discussed in detail. Furthermore, the Rastall parameter [Formula: see text] effect is analyzed for the collapse of sphere.

COUPLING OF DYNAMICAL AND TRANSPORT EQUATIONS IN f(R) THEORY

2013 ◽  
Vol 23 ◽  
pp. 276-280
Author(s):  
M. SHARIF ◽  
H. RIZWANA KAUSAR
Keyword(s):  
Heat Flux ◽  
Dark Energy ◽  
Transport Equation ◽  
Gravitational Collapse ◽  
Transport Equations ◽  
Anisotropic Fluid ◽  
Spherically Symmetric

This paper is devoted to study spherically symmetric gravitational collapse with anisotropic fluid in f(R) theory which undergoes dissipation in the form of heat flux. We develop dynamical and transport equation and finally couple them. This yields different possibilities of collapse and explosions connected with supernovae events and immense of dark energy terms arising from modifying gravity.

Collapsing of charged cylindrical symmetric source in f(R,G) gravity with heat flux

2020 ◽  
Vol 17 (02) ◽  
pp. 2050026
Author(s):  
Suhail Khan ◽  
Hassan Shah ◽  
Zahid Ahmad
Keyword(s):  
Heat Flux ◽  
Transport Equation ◽  
Gravitational Collapse ◽  
Positive Curvature ◽  
Higher Order ◽  
Anisotropic Pressure ◽  
Dynamical Equations ◽  
Symmetric Source ◽  
Text Model

This investigation deals with the dynamics of charged cylindrical gravitational collapse with anisotropic pressure and heat flux in [Formula: see text] gravity. For this purpose, we adopt the Misner–Sharp formalism to construct the dynamical equations and derive transport equation. Furthermore, we examine the collapsing rate by coupling the transport and dynamical equations. It is observed that the higher-order curvature terms influence the whole collapsing process such that the presence of positive curvature terms speeds up the collapsing process. It is also noted that for constant [Formula: see text] model the collapsing rate reduces.

scholarly journals Some geophysical constraints to dynamic processes in the Southwestern Mediterranean

1996 ◽  
Vol 39 (6) ◽  
Author(s):  
V. Pasquale ◽  
M. Verdoya ◽  
P. Chiozzi
Keyword(s):  
Heat Flux ◽  
Continental Crust ◽  
Gravitational Collapse ◽  
Seismic Activity ◽  
Thermal State ◽  
Dynamic Processes ◽  
Oceanic Spreading ◽  
Evolutionary Scheme ◽  
Alboran Basin ◽  
Tectonic Framework

The total tectonic subsidence, thermal state and seismotectonic regime have been analysed to better constrain the dynamic processes which originated the basins of the Southwestern Mediterranean. It is argued that backarc extension and oceanic spreading are the possible and main processes which took place within a compressional framework, driven by the interaction between the African and European plates. As inferred by both subsidence and heat-flux data, in the central part of the Algerian-Balearic basin the crust is oceanic, 20 Ma old on average, originated by a spreading phase, which also affected the Ligurian-Provençal basin. The Alboran basin, which is underlain by stretched continental crust, shows an intermediate seismic activity and a few deep events, explainable by a gravitational collapse of cold lithosphere. After a review of the most recent geodynamical hypotheses, an evolutionary scheme is attempted envisaging the lateral continental escape of the Gibraltar arc. Within a convergent tectonic framework, some lithospheric material could translate almost perpendicular to the convergence direction, and undergo a lateral subduction process, secondary to the main boundary between plates.

Convective Heat Transfer in Wall-Bounded Flows Affected by Severe Fluid Properties Variation: A Second-Moment Closure Study

2010 ◽  
Author(s):  
S. Jakirlic´ ◽  
R. Jester-Zu¨rker
Keyword(s):  
Heat Flux ◽  
Dissipation Rate ◽  
Transport Equations ◽  
Moment Closure ◽  
Reference Database ◽  
Turbulent Heat ◽  
Second Moment ◽  
Fluid Properties ◽  
Second Moment Closure ◽  
Near Wall

Different flow configurations subjected to increasingly enhanced wall heating were selected to be computationally investigated by means of a differential, near-wall second-moment closure model based on the solution of transport equations for second moments of the fluctuating velocities and temperature, ui″uj″͠ and ui″θ͠ respectively. Both Reynolds stress model and heat flux model represent wall-topography free formulations with quadratic pressure-strain term and pressure-temperature-gradient correlation. The transport equations for the turbulent stress tensor and the turbulent heat flux are solved in conjunction with the equation governing a new scale supplying variable, so-called “homogeneous” dissipation rate, Jakirlic and Hanjalic (2002). Such an approach offers a number of important advantages: proper near-wall shape of the dissipation rate profile was obtained without introducing any additional term and the correct asymptotic behaviour of the stress dissipation components by approaching the solid wall is fulfilled automatically without necessity for any wall geometry-related parameter. The configurations considered include fully-developed and developing flows in channel (without and with a sudden expansion) and pipe in conjunction with the scalar transport under conditions of variable fluid properties for which an extensive experimental and numerical (DNS and LES) reference database exists.

scholarly journals SPHERICALLY SYMMETRIC GRAVITATIONAL COLLAPSE OF A DUST CLOUD IN EINSTEIN–GAUSS–BONNET GRAVITY

2011 ◽  
Vol 26 (28) ◽  
pp. 2135-2147 ◽  
Author(s):  
KANG ZHOU ◽  
ZHAN-YING YANG ◽  
DE-CHENG ZOU ◽  
RUI-HONG YUE
Keyword(s):  
Cosmological Constant ◽  
Gravitational Collapse ◽  
Dust Cloud ◽  
Spherically Symmetric ◽  
Relativistic Case ◽  
Bonnet Gravity ◽  
Profound Influence ◽  
Dimensional Spacetime ◽  
General Relativistic ◽  
Bonnet Term

We explore the gravitational collapse of a spherically symmetric dust cloud in the Einstein–Gauss–Bonnet gravity without a cosmological constant, and obtain three families of LTB-like solutions. It is shown that the Gauss–Bonnet term has a profound influence on the nature of singularities, and the global structure of spacetime changes drastically from the analogous general relativistic case. Interestingly, the formation of a naked, massive and uncentral singularity, allowed in five-dimensional spacetime, is forbidden if D≥6. Moreover, such singularity is gravitational strong and a serious counterexample to CCH.

scholarly journals Dynamics of Dissipative Viscous Cylindrical Collapse with Full Causal Approach in f(R) Gravity

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
G. Abbas ◽  
H. Nazar
Keyword(s):  
Gravitational Collapse ◽  
Dynamical Equation ◽  
Mass Density ◽  
Inertial Mass ◽  
Theory Of Relativity ◽  
Viscous Heat ◽  
Source Case ◽  
Symmetric Geometry ◽  
Causal Approach ◽  
Physical Consequences

The idea of this article is to examine the effects on dynamics of dissipative gravitational collapse in nonstatic cylindrical symmetric geometry by using Misner-Sharp concept in framework of metric f(R) gravity theory. In this interest, we extended our study to the dissipative dark source case in both forms of heat flow and the free radiation streaming. Moreover, the role of different quantities such as heat flux, bulk, and shear viscosity in the dynamical equation is evaluated in thorough version. The dynamical equation is then coupled with full causal transportation equations in the context of Israel-Stewart formalism. The present scheme explains the physical consequences of the gravitational collapse and that is given in the decreasing form of inertial mass density which depends on thermodynamics viscous/heat coupling factors in background of f(R) theory of gravity. It is very interesting to tell us that the motives of this theory are reproduced for f(R)=R into general theory of relativity that has been done earlier.

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