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

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.

authors

• Dutta, Bhaskar

published proceedings

• JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS

altmetric score

• 8.33

author list (cited authors)

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

citation count

• 17

complete list of authors

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

publication date

• June 2017

publisher

• IOP Publishing  Publisher

published in

• Journal of Cosmology and Astroparticle Physics  Journal

keywords

• Dark Energy Theory
• Dark Matter Theory
• String Theory And Cosmology

Digital Object Identifier (DOI)

• 10.1088/1475-7516/2017/06/032

start page

• 032

end page

• 032

volume

• 2017

issue

• 6