Mass dimension one fermions in FLRW space-time

TL;DR

This paper investigates Elko, a mass dimension one fermion, in FLRW cosmology, providing exact solutions in de Sitter space and analyzing its potential as self-interacting dark matter.

Contribution

It presents the first exact solutions of Elko fermions in FLRW space-time, demonstrating their consistent quantum behavior and cosmological relevance.

Findings

Elko fields satisfy canonical anti-commutation relations.

Exact solutions are obtained in de Sitter space.

Elko exhibits properties suitable for dark matter models.

Abstract

Cosmelkology is the study of Elko in cosmology. Elko is a massive spin-half field of mass dimension one. Elko differs from the Dirac and Majorana fermions because it furnishes the irreducible representation of the extended Poincare group with a two-fold Wigner degeneracy where the particle and anti-particle states both have four degrees of freedom. Elko has a renormalizable quartic self interaction which makes it a candidate for self-interacting dark matter. We study Elko in the spatially flat FLRW space-time and find exact solutions in the de Sitter space. By choosing the appropriate solutions and phases, the fields satisfy the canonical anti-commutation relations and have the correct time evolutions in the flat space limit.