Strings, Branes and Cosmology: What can we hope to learn?

TL;DR

The article surveys how string theory and cosmology can inform one another, arguing that despite decoupling principles the interface is productive for understanding high-energy physics through the early universe. It discusses how branes reshaped naturalness considerations, enabling new inflationary scenarios via moduli stabilization and brane dynamics, and surveys the prospects for observable stringy signatures such as cosmic strings and high-energy EFT effects. Although embedding inflation in string theory is challenging and often requires tuning, certain modulus-driven constructions show promising naturalness in specific regimes, and current data such as WMAP3 are beginning to discriminate among classes of models. The work highlights how precision cosmology can test UV physics, constrain string vacua, and guide the search for viable models that connect fundamental theory to observable cosmology.

Abstract

This article briefly summarizes the motivations for -- and recent progress in -- searching for cosmological configurations within string theory, with a focus on how much we might reasonably hope to learn about fundamental physics from precision cosmological measurements.