Recent developments in string model-building and cosmology

TL;DR

This paper reviews recent advances in string model-building and cosmology, focusing on moduli stabilization, SUSY breaking, and inflationary models within type IIB string theory, highlighting their cosmological implications.

Contribution

It presents new insights into how string theory frameworks can explain cosmological phenomena like power loss at large scales and dark matter production.

Findings

Pre-inflationary dynamics can cause power loss at large scales.

String embeddings can produce various tensor mode amplitudes.

Reheating involves decay of the lightest modulus, producing dark matter and dark radiation.

Abstract

In this talk I discuss recent developments in moduli stabilisation, SUSY breaking and chiral D-brane models together with several interesting features of cosmological models built in the framework of type IIB string compactifications. I show that a non-trivial pre-inflationary dynamics can give rise to a power loss at large angular scales for which there have been mounting observational hints from both WMAP and Planck. I then describe different stringy embeddings of inflationary models which yield large or small tensor modes. I finally argue that reheating is generically driven by the decay of the lightest modulus which can produce, together with Standard Model particles, also non-thermal dark matter and light hidden sector degrees of freedom that behave as dark radiation.