Can I read The Axiverse induced Dark Radiation Problem on EtoBox?

The Axiverse induced Dark Radiation Problem by Acharya, Bobby Samir; Pongkitivanichkul, Chakrit is a scholarly article available to read on EtoBox.

What is The Axiverse induced Dark Radiation Problem about?

The string/$M$ theory Axiverse -- a plethora of very light Axion Like Particles (ALPs) with a vast range of masses -- is arguably a generic prediction of string/$M$ theory. String/$M$ theory also tends to predict that the early Universe is dominated by moduli fields. When the heavy moduli decay, before nucleosynthesis, they produce dark radiation in the form of relativistic ALPs. Generically one estimates that the number of relativistic species grows with the number of axions in the Axiverse, in contradiction to the observations that $N_{eff} \leq 4$. We explain this problem in detail and suggest some possible solutions to it. The simplest solution requires that the lightest modulus decays only into its own axion superpartner plus Standard Model particles and this severely constrains the moduli Kahler potential and mass matrix.

Author

Acharya, Bobby Samir; Pongkitivanichkul, Chakrit

Published

2015

Language

EN