String creation and cosmology

TL;DR

The paper explores how string creation could have contributed to the universe's reheating after inflation, focusing on effective field theory estimates and specific background models involving Neveu-Schwarz fields.

Contribution

It presents new estimates on string tension thresholds for significant string creation and discusses a unique background for studying closed string creation on the worldsheet.

Findings

String creation can significantly reheat the universe after inflation.

String tension needs to be just below the Planck scale for effective energy transfer.

A special background involving only Neveu-Schwarz fields allows for worldsheet studies of closed string creation.

Abstract

I argue that string creation may have played a role in reheating the universe after inflation. For strings in four dimensions that arise from branes wrapping cycles in the extra dimensions, estimates from effective field theory show that the string tension need only fall a couple of orders of magnitude below the Planck scale in order for string creation to extract a significant fraction of the energy in coherent motion of the inflaton field. I also comment on a special four-dimensional background which involves only Neveu-Schwarz fields and offers the possibility of studying closed string creation on the worldsheet.