Brane Interaction as the Origin of Inflation

TL;DR

This paper reexamines brane inflation driven by brane interactions at angles, showing it naturally leads to inflation ending with brane collision, and connects the string scale to the GUT scale based on cosmological observations.

Contribution

It introduces a new perspective on brane inflation involving angled brane interactions, including brane-anti-brane cases, and links string scale to GUT scale using observational data.

Findings

Inflation naturally occurs with brane interactions at angles.

Inflation ends with brane collision, leading to a big bang.

String scale is comparable to the GUT scale based on CMB data.

Abstract

We reanalyze brane inflation with brane-brane interactions at an angle, which include the special case of brane-anti-brane interaction. If nature is described by a stringy realization of the brane world scenario today (with arbitrary compactification), and if some additional branes were present in the early universe, we find that an inflationary epoch is generically quite natural, ending with a big bang when the last branes collide. In an interesting brane inflationary scenario suggested by generic string model-building, we use the density perturbation observed in the cosmic microwave background and the coupling unification to find that the string scale is comparable to the GUT scale.