Constraining Unparticle Physics with Cosmology and Astrophysics

TL;DR

This paper explores how cosmological and astrophysical observations can impose constraints on unparticle physics, a scale-invariant sector coupled to the Standard Model, and discusses potential relic densities of unparticles today.

Contribution

It introduces a method to constrain unparticle interactions using cosmology and astrophysics, highlighting their significance in testing unparticle theories.

Findings

Cosmology and astrophysics set strong bounds on unparticle-SM couplings.

Unparticle relic density could be significant today under certain conditions.

Unparticle phenomena are suppressed at low energies due to weak interactions.

Abstract

It has recently been suggested that a scale invariant "unparticle" sector with a non-trivial infrared fixed point may couple to the Standard Model (SM) via higher dimensional operators. The weakness of such interactions hides the the unparticle phenomena at low energies. We demonstrate how cosmology and astrophysics can place significant bounds on the strength of unparticle-SM interactions. We also discuss the possibility of a having a non-negligible unparticle relic density today.