D-term inflation without cosmic strings

TL;DR

This paper proposes a superstring-inspired D-term inflation model that avoids cosmic string formation by introducing a second pair of charged superfields, aligning with current CMB constraints.

Contribution

It introduces a novel superstring-inspired D-term inflation model with non-topological, BPS strings, differing from minimal models and naturally arising in brane scenarios.

Findings

Strings are non-topological (semilocal) and BPS.

Model satisfies current CMB constraints.

Second pair of superfields arises naturally in string scenarios.

Abstract

We present a superstring-inspired version of D-term inflation which does not lead to cosmic string formation and appears to satisfy the current CMB constraints. It differs from minimal D-term inflation by a second pair of charged superfields which makes the strings non-topological (semilocal). The strings are also BPS, so the scenario is expected to survive supergravity corrections. The second pair of charged superfields arises naturally in several brane and conifold scenarios, but its effect on cosmic string formation had not been noticed so far.