Mirror quintic vacua: hierarchies and inflation

TL;DR

This paper investigates the moduli space of type IIB string theory on mirror quintic Calabi-Yau, analyzing flux vacua, hierarchies, and potential inflationary regions through detailed period calculations and monodromy considerations.

Contribution

It provides a comprehensive analysis of flux vacua, hierarchies, and inflationary directions in mirror quintic compactifications, including solutions to Picard-Fuchs equations and multi-field inflation prospects.

Findings

Identifies flux vacua at various critical points, including conifold and orbifold.

Discovers inflationary regions involving multi-field dynamics, not single-field axion monodromy.

Highlights the importance of higher-order period expansions for stability and accurate vacua identification.

Abstract

We study the moduli space of type IIB string theory flux compactifications on the mirror of the CY quintic 3-fold in P4. We focus on the dynamics of the four dimensional moduli space, defined by the axio-dilaton {\tau} and the complex structure modulus z. The z-plane has critical points, the conifold, the orbifold and the large complex structure with non trivial monodromies. We find the solutions to the Picard-Fuchs equations obeyed by the periods of the CY in the full z-plane as a series expansion in z around the critical points to arbitrary order. This allows us to discard fake vacua, which appear as a result of keeping only the leading order term in the series expansions. Due to monodromies vacua are located at a given sheet in the z-plane. A dS vacuum appears for a set of fluxes. We revisit vacua with hierarchies among the 4D and 6D physical scales close to the conifold point and compare them with those found at leading order in [1, 2]. We explore slow-roll inflationary directions of the scalar potential by looking at regions where the multi-field slow-roll parameters {\epsilon} and {\eta} are smaller than one. The value of {\epsilon} depends strongly on the approximation of the periods and to achieve a stable value, several orders in the expansion are needed. We do not find realisations of single field axion monodromy inflation. Instead, we find that inflationary regions appear along linear combinations of the four real field directions and for certain configurations of fluxes.