# Fricke S-duality in CHL models

### APA

Volpato, R. (2015). Fricke S-duality in CHL models. Perimeter Institute. https://pirsa.org/15040124

### MLA

Volpato, Roberto. Fricke S-duality in CHL models. Perimeter Institute, Apr. 14, 2015, https://pirsa.org/15040124

### BibTex

@misc{ pirsa_PIRSA:15040124, doi = {10.48660/15040124}, url = {https://pirsa.org/15040124}, author = {Volpato, Roberto}, keywords = {Quantum Fields and Strings}, language = {en}, title = {Fricke S-duality in CHL models}, publisher = {Perimeter Institute}, year = {2015}, month = {apr}, note = {PIRSA:15040124 see, \url{https://pirsa.org}} }

Max Planck Institute for Gravitational Physics - Albert Einstein Institute (AEI)

Talk Type

**Subject**

Abstract

We consider dual pairs of four dimensional heterotic/type IIA CHL models with 16 space-time supersymmetries. We provide strong evidence for the existence of an S-duality acting on the heterotic axion-dilaton by a Fricke involution S --> -1/NS, where N is the order of the orbifold symmetry. While most models are self-dual, in some cases S-duality relates the CHL model to a compactification of type IIA on an orbifold of T^6. We provide a simple criterion to determine whether a model is self-dual or not. Finally, we argue that in self-dual CHL models the lattices of electric and magnetic charges must be N-modular and verify this prediction.