arXiv subjects

Ujjwal Agarwal

Publications and source records attributed to Ujjwal Agarwal.

3 recordsLinked to original sources

arXiv2026

A Covariant Distributional Approach for Junctions in Torsional Locally Rotationally Symmetric Class II Spacetimes

A rigorous framework for consistent study of junctions in a coordinate independent manner is presented. This is achieved by extending a theory of distributions in curved spacetimes with torsion and combining it with covariant formalism. In this way, one can derive general conditions on the differentiability of the joined manifold. Given a specific theory of gravity, in particular the Einstein-Cartan-Sciama-Kibble one, we evaluate the conditions for obtaining a smooth junction. These conditions can be successfully applied independently of the choice of coordinates used to describe the metric, thereby, evading the drawbacks of coordinate dependent Israel-Darmois framework.

gr-qc↗

arXiv2025

Locally Rotationally Symmetric Spacetimes in Einstein-Cartan Theory and Their Classification

We present the complete set of covariant equations that govern the locally rotationally symmetric torsion spacetimes sourced by Weyssenhoff fluid in Einstein-Cartan-Sciama-Kibble gravity. Using these equations, we can explore in detail the peculiar relationship between conformal structure and torsion. We develop a comprehensive scheme to categorize these torsional spacetimes into distinct classes. We explicitly analyze the properties of each class and obtain novel analytical solutions to the gravitational field equations.

gr-qc↗

arXiv2024

Toward Singularity Theorems with Torsion

This study examines the formulation of a singularity theorem for timelike curves including torsion, and establishes the foundational framework necessary for its derivation. We begin by deriving the relative acceleration for an arbitrary congruence of timelike curves. The resulting ``deviation equation'' offers an alternative pathway to the well-known Raychaudhuri equation with torsion. Conjugate points are then introduced and analyzed in relation to the behavior of the scalar expansion. Together with the sensible requirement of hypersurface orthogonality, the Raychaudhuri equation is examined for several specific cases of torsion that are prominent in the literature. Our findings indicate that a totally antisymmetric torsion tensor does not influence the behavior of the congruence of timelike curves. Finally, we formulate a singularity theorem for timelike curves and highlight the critical requirement of non-autoparallel curves.

gr-qc↗