Non-Geodesic Incompleteness in Poincaré Gauge Gravity.

José Cembranos,Jorge Valcarcel,Francisco Torralba

doi:10.3390/e21030280

José Cembranos, Jorge Valcarcel + Show 1 more

Open Access

https://doi.org/10.3390/e21030280

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Abstract

In this work, we review the study of singularities in Poincaré gauge theories of gravity. Since one of the most recent studies used the appearance of black hole regions of arbitrary dimension as an indicator of singular behavior, we also give some explicit examples of these structures and study how particles behave around them.

Highlights

Can spin avert singularities? This is a question that has been under study since Stewart and Hajicek proposed that the presence of torsion, sourced by half-spin particles, would lead to the avoidance of singularities in the spacetime [1]
We conclude that if these kinds of structures exist in our spacetime, we would have timelike curves that do not have endpoints in the conformal infinity, since for the case of black hole (BH), the spacetime M is not contained in J − (J + ), while for WHs, M is not contained in J + (J − )
We have shown that the occurrence of singularities within strongly asymptotically-predictable spacetimes cannot be avoided by the introduction of the torsion tensor into their geometric structure

Summary

Introduction

Can spin avert singularities? This is a question that has been under study since Stewart and Hajicek proposed that the presence of torsion, sourced by half-spin particles, would lead to the avoidance of singularities in the spacetime [1]. The reasoning that one can follow to answer if the introduction of new geometrical degrees of freedom can avoid the appearance of singularities is to study if the standard conditions exposed in this theorem may change in the framework under consideration. In this sense, the authors proved in [4].

Generalities of Theories with Torsion

The Singularity Theorem

Reissner–Nordström Sourced by Torsion

Fermion Dynamics

Conclusions