Vacuum Energy Cancellation in a Non-supersymmetric String

TL;DR

This paper constructs a non-supersymmetric string model with a vanishing cosmological constant at multiple loop levels, suggesting potential stability without supersymmetry.

Contribution

It introduces a specific orbifold of type II string theory demonstrating vacuum energy cancellation without supersymmetry, a novel approach in string theory.

Findings

Vanishing cosmological constant at one and two loops

Heuristic argument for higher-loop cancellation

Potential implications for non-supersymmetric string stability

Abstract

We present a nonsupersymmetric orbifold of type II string theory and show that it has vanishing cosmological constant at the one and two loop level. We argue heuristically that the cancellation persists at higher loops.