On Warped String Vacuum Profiles and Cosmologies, II. Non-Supersymmetric Strings

TL;DR

This paper explores non-supersymmetric string vacua in warped geometries, analyzing their asymptotics, flux configurations, and cosmological behaviors, revealing new classes of solutions with finite boundaries and diverse asymptotic properties.

Contribution

It introduces new exact solutions for non-supersymmetric string vacua with fluxes, detailing their asymptotics and cosmological implications, expanding understanding of string cosmology beyond supersymmetric models.

Findings

Identified two families of vacua for orientifold potentials with finite internal intervals.

Discovered four types of heterotic vacua with diverse asymptotic behaviors.

Presented three families of exact solutions including supersymmetric limits and various asymptotics.

Abstract

We investigate the effects of the leading tadpole potentials of 10D tachyon-free non-supersymmetric strings in warped products of flat geometries of the type M(p+1) x R x T(10-p-2) depending on a single coordinate. In the absence of fluxes and for p<8, there are two families of these vacua for the orientifold disk-level potential, both involving a finite internal interval. Their asymptotics are surprisingly captured by tadpole-free solutions, isotropic for one family and anisotropic at one end for the other. In contrast, for the heterotic torus-level potential there are four types of vacua. Their asymptotics are always tadpole-dependent and isotropic at one end lying at a finite distance, while at the other end, which can lie at a finite or infinite distance, they can be tadpole-dependent isotropic or tadpole-free anisotropic. We then elaborate on the general setup for including symmetric fluxes, and present the three families of exact solutions that emerge when the orientifold potential and a seven-form flux are both present. These solutions include a pair of boundaries, which are always separated by a finite distance. In the neighborhood of one, they all approach a common supersymmetric limit, while the asymptotics at the other boundary can be tadpole-free isotropic, tadpole-free anisotropic or again supersymmetric. We also discuss corresponding cosmologies, with emphasis on their climbing or descending behavior at the initial singularity. In some cases the toroidal dimensions can contract during the cosmological expansion.