Dark matter relics and the expansion rate in scalar-tensor theories Academic Article uri icon

abstract

  • © 2017 IOP Publishing Ltd and Sissa Medialab. We study the impact of a modified expansion rate on the dark matter relic abundance in a class of scalar-tensor theories. The scalar-tensor theories we consider are motivated from string theory constructions, which have conformal as well as disformally coupled matter to the scalar. We investigate the effects of such a conformal coupling to the dark matter relic abundance for a wide range of initial conditions, masses and cross-sections. We find that exploiting all possible initial conditions, the annihilation cross-section required to satisfy the dark matter content can differ from the thermal average cross-section in the standard case. We also study the expansion rate in the disformal case and find that physically relevant solutions require a nontrivial relation between the conformal and disformal functions. We study the effects of the disformal coupling in an explicit example where the disformal function is quadratic.

published proceedings

  • Journal of Cosmology and Astroparticle Physics

altmetric score

  • 8.33

author list (cited authors)

  • Dutta, B., Jimenez, E., & Zavala, I

citation count

  • 15

complete list of authors

  • Dutta, Bhaskar||Jimenez, Esteban||Zavala, Ivonne

publication date

  • June 2017