String production at the level of effective field theory

Abstract

Pair creation of strings in time-dependent backgrounds is studied from an\neffective field theory viewpoint, and some possible cosmological applications\nare discussed. Simple estimates suggest that excited strings may have played a\nsignificant role in preheating, if the string tension as measured in\nfour-dimensional Einstein frame falls a couple of orders of magnitude below the\nfour-dimensional Planck scale.\n