Work

Raychaudhuri equations and gravitational collapse in Einstein-Cartan theory

Year: 2021

Type: article

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 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 nonzero torsion, i.e., if the collapsing dust particles possess intrinsic spin.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/physrevd.104.084073

Authors: Sudipta Hensh, Stefano Liberati

Institutions: Silesian University in Opava, Scuola Internazionale Superiore di Studi Avanzati, Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Institute for Fundamental Physics of the Universe

Language: English

Topic: Cosmology and Gravitation Theories

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: Ministero dell’Istruzione, dell’Università e della Ricerca, Slezská Univerzita v Opavě

Awards: G3300836185, G4590720103, G475601001