Colliding Singularities in F-theory and Phase Transitions

TL;DR

This paper investigates how colliding singularities in F-theory lead to phase transitions involving tensionless strings, new tensor multiplets, and enhanced gauge symmetries, revealing complex dynamics of small instantons.

Contribution

It uncovers the connection between singularity resolutions in F-theory and phase transitions with tensionless strings and multiple small instantons shrinking simultaneously.

Findings

Resolutions of singularities correspond to phases with new tensor multiplets.

Phase transitions involve tensionless strings and enhanced gauge symmetry.

Identification of new transition points with multiple small instantons shrinking.

Abstract

We study F-theory on elliptic threefold Calabi-Yau near colliding singularities. We demonstrate that resolutions of those singularities generically correspond to transitions to phases characterized by new tensor multiplets and enhanced gauge symmetry. These are governed by the dynamics of tensionless strings. We also find new transition points which are associated with several small instantons simultaneously shrinking to zero size.