scholarly journals Thermal nature of a generic null surface

2021 ◽  
Vol 104 (12) ◽  
Author(s):  
Surojit Dalui ◽  
Bibhas Ranjan Majhi ◽  
T. Padmanabhan
Keyword(s):  
Null Surface

Gravitational synchrotron radiation in the metric of a new theory of gravitation

1980 ◽  
Vol 58 (11) ◽  
pp. 1595-1598 ◽  
Author(s):  
R. B. Mann ◽  
J. W. Moffat
Keyword(s):  
Black Hole ◽  
Wave Equation ◽  
Synchrotron Radiation ◽  
Gravitational Radiation ◽  
Field Structure ◽  
Astrophysical Object ◽  
Schwarzschild Black Hole ◽  
Null Surface ◽  
Strong Source ◽  
Theory Of Gravitation

The wave equation for a scalar field ψ is solved in the background metric of a new theory of gravity, based on a non-Riemannian field structure with a nonsymmetric Hermitian gμν. In contrast to the solution of the problem in a Schwarzschild background metric, in which only orbits close to r ~ 3M yield significant gravitational radiation, the new metric leads to an effective potential with stable orbits for a substantial range of r. The solution yields ψ = (1 − ℓ4/r4)−1/2ψGR where ℓ is a new integration constant. The null surface r = ℓ determines an astrophysical object called a "deflectar", which for ℓ > 2M conceals the Schwarzschild black-hole event horizon at r = 2M. As r → ℓ the gravitational synchrotron radiation increases to infinity. The actual power output of gravitational radiation for physically allowed stable orbits closest to r = ℓ is estimated, demonstrating that a deflectar is a potentially strong source of gravitational radiation.

Asymptotic structure of the null surface formulation and the classical graviton

2016 ◽  
Vol 94 (10) ◽  
Author(s):  
Melina Bordcoch ◽  
Carlos N. Kozameh ◽  
Teresita A. Rojas
Keyword(s):  
Asymptotic Structure ◽  
Null Surface ◽  
Null Surface Formulation

THE HYDRODYNAMICS OF ATOMS OF SPACETIME: GRAVITATIONAL FIELD EQUATION IS NAVIER–STOKES EQUATION

2011 ◽  
Vol 20 (14) ◽  
pp. 2817-2822 ◽  
Author(s):  
T. PADMANABHAN
Keyword(s):  
Gravitational Field ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Field Equations ◽  
Gravitational Field Equation ◽  
Navier Stokes Equation ◽  
Navier Stokes Equations ◽  
Gravitational Field Equations ◽  
Conceptual Status ◽  
Null Surface

There is considerable evidence to suggest that field equations of gravity have the same conceptual status as the equations of hydrodynamics or elasticity. We add further support to this paradigm by showing that Einstein"s field equations are identical in form to Navier–Stokes equations of hydrodynamics, when projected on to any null surface. In fact, these equations can be obtained directly by extremizing of entropy associated with the deformations of null surfaces thereby providing a completely thermodynamic route to gravitational field equations. Several curious features of this remarkable connection (including a phenomenon of "dissipation without dissipation") are described and the implications for the emergent paradigm of gravity is highlighted.

scholarly journals Quantization of the null-surface formulation of general relativity

1997 ◽  
Vol 56 (2) ◽  
pp. 889-907 ◽  
Author(s):  
Simonetta Frittelli ◽  
Carlos N. Kozameh ◽  
Ezra T. Newman ◽  
Carlo Rovelli ◽  
Ranjeet S. Tate
Keyword(s):  
General Relativity ◽  
Null Surface ◽  
Null Surface Formulation

scholarly journals Noncommutative Heisenberg algebra in the neighbourhood of a generic null surface

2018 ◽  
Vol 934 ◽  
pp. 557-577 ◽  
Author(s):  
Krishnakanta Bhattacharya ◽  
Bibhas Ranjan Majhi
Keyword(s):  
Heisenberg Algebra ◽  
Null Surface

scholarly journals EXTENDED PLANCK SCALE

2003 ◽  
Vol 18 (15) ◽  
pp. 1037-1042 ◽  
Author(s):  
F. I. COOPERSTOCK ◽  
V. FARAONI
Keyword(s):  
Z Boson ◽  
Mass Spectra ◽  
Planck Scale ◽  
Structure Constant ◽  
High Energy ◽  
Fine Structure Constant ◽  
High Energy Radiation ◽  
Planck Mass ◽  
Null Surface

Traditional derivations of the Planck mass ignore the role of charge and spin in general relativity. From the Kerr–Newman null surface and horizon radii, quantized charge and spin dependence are introduced in an extended Planck scale of mass. Spectra emerge with selection rules dependent upon the choice of Kerr–Newman radius to link with the Compton wavelength. The appearance of the fine structure constant suggests the possibility of a variation in time of the extended Planck mass, which may be much larger than the variation in the traditional one. There is a suggestion of a connection with the α value governing high-energy radiation in Z-boson production and decay.

A new type of singularity created by colliding gravitational waves

1986 ◽  
Vol 408 (1835) ◽  
pp. 175-208 ◽  
Keyword(s):  
Gravitational Waves ◽  
Space Time ◽  
Kerr Metric ◽  
Analytic Extension ◽  
Type D ◽  
Null Surface ◽  
Kerr Space ◽  
New Type ◽  
Colliding Gravitational Waves ◽  
Petrov Type D

An exact solution is obtained for colliding plane impulsive gravitational waves accompanied by shock waves, which, in contrast to other known solutions, results in the development of a null surface which acts like an event horizon. The analytic extension of the solution across the null surface reveals the existence of time-like curvature singularities along two hyperbolic arcs in the extended domain, reminiscent of the ring singularity of the Kerr metric. Besides, the space-time, in the region of the interaction of the colliding waves, is of Petrov-type D and locally isometric to the Kerr space-time in a region interior to the ergosphere. Various other aspects of the solution are also discussed.

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