Hawking radiation of unparticles

TL;DR

This paper investigates how unparticles, hypothetical entities with non-integer scaling dimensions, influence black hole radiation, potentially dominating emission channels and affecting observable signatures in models with low-scale quantum gravity.

Contribution

Develops a method to calculate grey-body factors for scalar unparticles in black hole backgrounds, revealing their potential dominance in Hawking radiation.

Findings

Unparticles can significantly alter black hole emission spectra.

Unparticles may dominate over standard particles in certain models.

Results depend on unparticle normalization, which is currently uncertain.

Abstract

Unparticle degrees of freedom, no matter how weakly coupled to the standard model particles, must affect the evolution of a black hole, which thermally decays into all available degrees of freedom. We develop a method for calculating the grey-body factors for scalar unparticles for 3+1 and higher dimensional black holes. We find that the power emitted in unparticles may be quite different from the power emitted in ordinary particles. Depending on the parameters in the model, unparticles may become the dominant channel. This is of special interest for small primordial black holes and also in models with low scale quantum gravity where the experimental signature may significantly be affected. We also discuss the sensitivity of the results on the (currently unknown) unparticle normalization.