arXiv subjects

Miguel Hernandez-Segura

Publications and source records attributed to Miguel Hernandez-Segura.

3 recordsLinked to original sources

arXiv2026

The Flavor of Non-Abelian Orbifolds

In string model building, flavor symmetries can arise from the geometric features of the compactification space. In the case of heterotic orbifold models, modular and traditional flavor symmetries can be related to both geometric and algebraic properties of the orbifold space group. Our goal is to study the origin of moduli-independent discrete flavor symmetries in symmetric heterotic orbifolds with non-Abelian point groups. We develop various methods based on the Abelianization and the geometric automorphisms of the orbifold space group to determine these symmetries and their associated charges for matter fields. Notably, our methods were applied to all 331 non-Abelian affine geometries, including roto-translations, suitable for delivering N=1 supersymmetric heterotic compactifications in four dimensions. This provides additional motivation to pursue the derivation of new types of phenomenologically viable models from string theory.

hep-th↗

arXiv2026

Rolling with modular symmetry: quintessence and de Sitter in heterotic orbifolds

Modular invariance is a fundamental symmetry in string compactifications, constraining both the structure of the effective theory and the dynamics of moduli and matter fields. It has also gained renewed importance in the context of swampland conjectures and, independently, flavour physics. We investigate a modular-invariant scalar potential arising from heterotic orbifolds, where the flavour structure and moduli dynamics are jointly shaped by the underlying geometry. Focusing on a string-inspired, two-moduli truncation, we uncover a rich vacuum structure featuring anti-de Sitter minima and unstable de Sitter saddle points. We identify large regions in moduli space supporting multifield hilltop quintessence consistent with observations. All solutions satisfy refined swampland de Sitter bounds. Our results illustrate how modular symmetry can guide the construction of controlled, string-motivated quintessence scenarios within consistent effective theories.

hep-th↗

arXiv2025

Non-Abelian orbifolds of the SO(32) heterotic string

Non-Abelian toroidal heterotic orbifolds have received comparatively little attention, mainly because of the significant computational challenges they pose, even at the level of computing their matter spectrum. Similarly, the SO(32) heterotic string remains relatively unexplored. In this paper, we provide some useful tools to handle this situation. We find that certain non-Abelian orbifolds can be studied using the techniques that are common to Abelian compactifications. In such cases, we show how to compute the gauge groups and massless matter spectrum for non-Abelian orbifolds of the SO(32) heterotic string with standard embedding. A general feature of these constructions is the reduction of the rank of the gauge group. Our findings motivate further research on non-Abelian orbifolds with non-standard embedding, where realistic, rank-reduced models are expected to emerge.

hep-th↗