Parity violation in four and higher dimensional spacetime with torsion

TL;DR

This paper investigates parity violation in gravitational theories with torsion across four and higher dimensions, analyzing conditions for parity conservation and the effects of compactification schemes on parity-violating terms.

Contribution

It provides a comprehensive analysis of parity violation in torsion-inclusive gravity theories in multiple dimensions, including effects of string-inspired dualities and compactification.

Findings

Parity may or may not be conserved depending on torsion antisymmetry.

Torsion-axion duality preserves parity in the gravity sector across dimensions.

Parity-violating interactions for fermions can have significant phenomenological impacts.

Abstract

The possibility of parity violation in a gravitational theory with torsion is extensively explored in four and higher dimensions. In the former case,we have listed our conclusions on when and whether parity ceases to be conserved, with both two-and three-index antisymmetry of the torsion field. In the latter, the bulk spacetime is assumed to have torsion, and the survival of parity-violating terms in the four dimensional effective action is studied, using the compactification schemes proposed by Arkani-Hamed-Dimopoulos-Dvali and Randall-Sundrum. An interesting conclusion is that the torsion-axion duality arising in a stringy scenario via the second rank antisymmetric Kalb-Ramond field leads to conservation of parity in the gravity sector in any dimension. However, parity-violating interactions do appear for spin 1/2 fermions in such theories, which can have crucial phenomenological implications.