Eur. Phys. J. C (2019) 79: 696
https://doi.org/10.1140/epjc/s10052-019-7200-y

Letter

Rest frame vacuum of the Dirac field on spatially flat FLRW spacetimes

West University of Timişoara, V. Pârvan Ave. 4, 300223, Timişoara, Romania

^* e-mail: i.cotaescu@e-uvt.ro

Received: 2 June 2019
Accepted: 3 August 2019
Published online: 19 August 2019

Abstract

In quantum theory of the free Dirac field on spatially flat FLRW spacetimes we introduce a new type of vacuum able to separate the positive and negative frequencies in the rest frames. This is called here the rest frame vacuum showing that this differs from the adiabatic vacuum apart from the Minkowski spacetime where these two vacua coincide.