IR finite graviton propagators in de Sitter spacetime

The European Physical Journal C

Mir Faizal¹  Bhabani Prasad Mandal²  Sudhaker Upadhyay² 

[1] Department of Physics and Astronomy, University of Lethbridge, T1K 3M4, Lethbridge, AB, Canada;Department of Physics, Banaras Hindu University, 221005, Varanasi, India;

关键词: Gauge Parameter;    BRST Transformation;    Ghost Propagator;    Inflaton Field;    Initial Gauge;   

DOI  :  10.1140/epjc/s10052-016-4008-x

来源: Springer

【 摘 要 】

The graviton propagator diverges in certain gauges in de Sitter spacetime. We address this problem in this work by generalizing the infinitesimal BRST transformations in de Sitter spacetime to finite field-dependent BRST (FFBRST) transformations. These FFBRST transformations are a symmetry of the classical action, but they do not leave the path integral measure invariant for the graviton theory in de Sitter spacetime. Due to the non-trivial Jacobian of such a finite transformation the path integral measure changes and hence the FFBRST transformation is capable of relating theories in two different gauges. We explicitly construct the FFBRST transformation which relates the theory with a diverging graviton two-point function to a theory with an infrared finite graviton. The FFBRST transformation thus establishes that the divergence in a graviton two-point function may be only a gauge artifact.

【 授权许可】

CC BY