A simple parity violating gravity model without ghost instability

Autor:	Li, Mingzhe, Rao, Haomin, Zhao, Dehao
Rok vydání:	2020
Předmět:	General Relativity and Quantum Cosmology Astrophysics - Cosmology and Nongalactic Astrophysics High Energy Physics - Theory
Druh dokumentu:	Working Paper
DOI:	10.1088/1475-7516/2020/11/023
Popis:	In this paper we consider a parity violating gravity model without higher derivatives, thus ghost free. This model is constructed from the tetrad and its derivatives and coupled to a dynamical scalar field, like axion. It can be reduced from the Nieh-Yan term within the framework of teleparallel gravity. We apply this model to cosmology and investigate its consequences on cosmological perturbation theory. We find that the coupled dynamical scalar field lost its independent dynamics at the linear order and the parity violating term itself behaves like a viscosity. For gravitational waves, this model produces velocity difference between left- and right-handed polarizations, but generates no amplitude discrepancy. Comment: The version matches the one to appear in JCAP
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2007.08038 Zobrazit plný text záznamu View this record from Arxiv