Problems of classical and quantum gravitational collapse. II (general relativistic hamiltonian dynamics of a perfect fluid)

1977 ◽  
Vol 20 (4) ◽  
pp. 533-538
Author(s):  
V. N. Ponomarev ◽  
V. G. Krechet ◽  
A. O. Barvinskii
Keyword(s):  
Perfect Fluid ◽  
Gravitational Collapse ◽  
Hamiltonian Dynamics ◽  
General Relativistic ◽  
Relativistic Hamiltonian Dynamics

All classical predictions of general relativity from special relativistic Hamiltonian dynamics

2018 ◽  
Vol 33 (29) ◽  
pp. 1850169
Author(s):  
J. H. Field
Keyword(s):  
General Relativity ◽  
Euclidean Space ◽  
Hamiltonian Dynamics ◽  
Gravitational Redshift ◽  
Newtonian Mechanics ◽  
Light Deflection ◽  
Schwarzschild Metric ◽  
Related Literature ◽  
General Relativistic ◽  
Relativistic Hamiltonian Dynamics

Previous special relativistic calculations of gravitational redshift, light deflection and Shapiro delay are extended to include perigee advance. The three classical, order G, post-Newtonian predictions of general relativity as well as general relativistic light-speed-variation are therefore shown to be also consequences of special relativistic Newtonian mechanics in Euclidean space. The calculations are compared to general relativistic ones based on the Schwarzschild metric equation, and related literature is critically reviewed.

scholarly journals Improved dynamics and gravitational collapse of tachyon field coupled with a barotropic fluid

2015 ◽  
Vol 24 (03) ◽  
pp. 1550025 ◽  
Author(s):  
João Marto ◽  
Yaser Tavakoli ◽  
Paulo Vargas Moniz
Keyword(s):  
Black Hole ◽  
Gravitational Collapse ◽  
Classical Model ◽  
Saddle Points ◽  
Tachyon Field ◽  
Naked Singularities ◽  
Barotropic Fluid ◽  
Gravity Effects ◽  
Present Context ◽  
General Relativistic

We consider a spherically symmetric gravitational collapse of a tachyon field with an inverse square potential, which is coupled with a barotropic fluid. By employing an holonomy correction imported from loop quantum cosmology (LQC), we analyze the dynamics of the collapse within a semiclassical description. Using a dynamical system approach, we find that the stable fixed points given by the standard general relativistic setting turn into saddle points in the present context. This provides a new dynamics in contrast to the black hole and naked singularities solutions appearing in the classical model. Our results suggest that classical singularities can be avoided by quantum gravity effects and are replaced by a bounce. By a thorough numerical studies we show that, depending on the barotropic parameter γ, there exists a class of solutions corresponding to either a fluid or a tachyon dominated regimes. Furthermore, for the case γ ~ 1, we find an interesting tracking behavior between the tachyon and the fluid leading to a dust-like collapse. In addition, we show that, there exists a threshold scale which determines when an outward energy flux emerges, as a nonsingular black hole is forming, at the corresponding collapse final stages.

scholarly journals Charged Perfect Fluid Cylindrical Gravitational Collapse

2011 ◽  
Vol 80 (10) ◽  
pp. 104002 ◽  
Author(s):  
Muhammad Sharif ◽  
Ghulam Abbas
Keyword(s):  
Perfect Fluid ◽  
Gravitational Collapse

On the classical and quantum irrotational motions of a relativistic perfect fluid I. Classical theory

1985 ◽  
Vol 401 (1820) ◽  
pp. 53-66 ◽  
Keyword(s):  
Perfect Fluid ◽  
Vacuum State ◽  
Background Field ◽  
Field Configuration ◽  
Spontaneous Breaking ◽  
Sound Waves ◽  
Action Functional ◽  
Fluid Equation ◽  
Goldstone Bosons ◽  
General Relativistic

Some aspects of perfect-fluid general-relativistic hydrodynamics under the assumptions of irrotationality and isentropicity are analysed. A new derivation of the known fact that the Lagrangian for these fluids is just the pressure is given. Then we study the fluctuations around a given background field configuration, extracting a rule that connects the order at which a Taylor expansion of the action functional possibly stops with the fluid equation of state. From a classical invariance of the action we deduce the conserved Noether current. Because of the spontaneous breaking of such an invariance on the vacuum state Goldstone bosons arise, which turn out to be just phonons (quantized sound waves). Some useful results concerning the linear theory of sound waves are also given.

DOES PRESSURE ACCENTUATE GENERAL RELATIVISTIC GRAVITATIONAL COLLAPSE AND FORMATION OF TRAPPED SURFACES?

2013 ◽  
Vol 22 (05) ◽  
pp. 1350021 ◽  
Author(s):  
ABHAS MITRA
Keyword(s):  
General Relativity ◽  
Gravitational Collapse ◽  
Fluid Pressure ◽  
Free Fall ◽  
Newtonian Gravity ◽  
Tangential Pressure ◽  
Trapped Surfaces ◽  
Imperfect Fluid ◽  
Newtonian Case ◽  
General Relativistic

It is widely believed that though pressure resists gravitational collapse in Newtonian gravity, it aids the same in general relativity (GR) so that GR collapse should eventually be similar to the monotonous free fall case. But we show that, even in the context of radiationless adiabatic collapse of a perfect fluid, pressure tends to resist GR collapse in a manner which is more pronounced than the corresponding Newtonian case and formation of trapped surfaces is inhibited. In fact there are many works which show such collapse to rebound or become oscillatory implying a tug of war between attractive gravity and repulsive pressure gradient. Furthermore, for an imperfect fluid, the resistive effect of pressure could be significant due to likely dramatic increase of tangential pressure beyond the "photon sphere." Indeed, with inclusion of tangential pressure, in principle, there can be static objects with surface gravitational redshift z → ∞. Therefore, pressure can certainly oppose gravitational contraction in GR in a significant manner in contradiction to the idea of Roger Penrose that GR continued collapse must be unstoppable.

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.

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