Non-Supersymmetric String-String Dualities via Enriques Surfaces

TL;DR

This work proposes non-supersymmetric analogues of well-known six-dimensional string dualities by quotienting K3 to Enriques, and shows that Type II on Enriques and Type 0 theories can be linked to non-supersymmetric heterotic asymmetric orbifolds. It develops explicit non-supersymmetric orbifolds of Type II via a fixed-point-free involution on K3, analyzes the full untwisted and twisted sector spectra including tachyons, and reinterprets the setup in terms of Type 0 gravity, arguing a duality map that mirrors the supersymmetric K3 story. By leveraging the Enriques quotient, the paper extends the web of dualities to non-supersymmetric settings, with detailed accounting of moduli spaces and massless spectra, while highlighting the tachyonic complications and potential non-perturbative resolutions at strong coupling. The results suggest a framework in which non-supersymmetric dualities can be studied through Enriques geometry, offering a concrete bridge between Type II, Type 0, and heterotic theories and insights into how tachyons and RR sectors behave across dual pairs in non-supersymmetric contexts.

Abstract

We propose non-supersymmetric analogues of 6d N=2 Type II/heterotic dualities via a quotient of a K3 surface: an Enriques surface. We start from Type~II strings on a K3 surface and construct orbifold theories using an involution of K3. We extract the massless and tachyonic spectra and identify the moduli spaces locally. We further reinterpret the constructions as Type 0A/0B strings compactified on an Enriques surface, and argue that the theories are dual to recently constructed non-supersymmetric heterotic asymmetric orbifolds.

Figures (4)

• Figure 1: A schematic picture.
• Figure 2: Modular transformations of partition function on $T^4/\mathbb{Z}_2$.
• Figure 3: A schematic picture.
• Figure 4: Modular transformations of partition function on $T^4/\mathbb{Z}_2$