Raychaudhuri equations and gravitational collapse in Einstein-Cartan theory

Abstract

The Raychaudhuri equations for the expansion, shear and vorticity are generalized in a spacetime with torsion for timelike as well as null congruences. These equations are purely geometrical like the original Raychaudhuri equations and could be reduced to them when there is no torsion. Using the Einstein-Cartan-Sciama-Kibble field equations the effective stress-energy tensor is derived. We also consider an Oppenheimer-Snyder model for the gravitational collapse of dust. It is shown that the null energy condition (NEC) is violated before the density of the collapsing dust reaches the Planck density, hinting that the spacetime singularity may be avoided if there is a non-zero torsion,i.e. if the collapsing dust particles possess intrinsic spin.

References in corpus (15)

• f(T) teleparallel gravity and cosmology
• Black hole fireworks: quantum-gravity effects outside the horizon spark black to white hole tunneling
• The Raychaudhuri equations: a brief review
• White Holes as Remnants: A Surprising Scenario for the End of a Black Hole
• Geodesically complete black holes
• Classical collapse to black holes and quantum bounces: A review
• Opening the Pandora's box at the core of black holes
• Mutiny at the white-hole district
• The Raychaudhuri equation in spacetimes with torsion and non-metricity
• Kinematics of Einstein-Cartan universes
• Spacetime thermodynamics in the presence of torsion
• Raychaudhuri equation in spacetimes with torsion
• Collapse and dispersal of a homogeneous spin fluid in Einstein-Cartan theory
• Effect of Spin-Torsion Interaction on Raychaudhuri Equation
• Raychaudhuri and optical equations for null geodesic congruences with torsion

Cited by in corpus (12)

• Gravitational waves at the first post-Newtonian order with the Weyssenhoff fluid in Einstein-Cartan theory
• Kinematics and dynamics of null hypersurfaces in the Einstein-Cartan spacetime and related thermodynamic interpretation
• Kinematics in Metric-Affine Geometry
• NEC violation in $f(\bar{R},\bar{T})$ gravity in the context of a non-canonical theory via modified Raychaudhuri equation
• Non-Affine Extensions of the Raychaudhuri Equation in the K-essence Framework
• Lagrangian Formulation of the Raychaudhuri Equation in Non-Riemannian Geometry
• Evolution of the early universe in Einstein-Cartan theory
• Tidal heating in a Riemann-Cartan spacetime
• Exploring Cosmological Implications of the Modified Raychaudhuri Equation in Non-Gravitating Vacuum Energy Theory
• From Geometry to Observation: Gravitational Waves and the Raychaudhuri Equation
• Torsional four-fermion interaction and the Raychaudhuri equation
• Possible fluid interpretation and tidal force equation on a generic null hypersurface in Einstein-Cartan theory