Misaligned supersymmetry and open strings

Niccolò Cribiori,Flavio Tonioni,Timm Wrase,Susha Parameswaran

doi:10.1007/jhep04(2021)099

Niccolò Cribiori, Flavio Tonioni + Show 2 more

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https://doi.org/10.1007/jhep04(2021)099

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Abstract

The study of non-supersymmetric string theories is shedding light on an important corner of the string landscape and might ultimately explain why, so far, we did not observe supersymmetry in our universe. We review how misaligned supersymmetry in closed-string theories leads to a cancellation between bosons and fermions even in non-supersymmetric string theories. We then show that the same cancellation takes place for open strings by studying an anti-Dp-brane placed on top of an Op-plane in type II string theory. Misaligned supersymmetry consists in cancellations between bosons and fermions at different energy levels, in such a way that the averaged number of states grows at a rate dominated by a factor {mathrm{e}}^{C_{mathrm{e}mathrm{ff}}sqrt{n}} , with Ceff< Ctot, where Ctot is the inverse Hagedorn temperature. We prove the previously conjectured complete cancellation, i.e. we prove that Ceff = 0, for a vast class of models.

Highlights

Misaligned supersymmetry consists in cancellations between bosons and fermions at different energy levels, in such a way that the averaged number of states grows at a rate dominated by a factor eCeff n, with Ceff < Ctot, where Ctot is the inverse Hagedorn temperature
In closed-string theories, the cancellations implied by misaligned supersymmetry occur precisely in accordance with the way modular invariance fixes the couplings among sectors: changing these couplings would in general spoil modular invariance and prevent such cancellations from occurring
In order to do that, we specialise our discussion to the case in which the partition function can be written entirely in terms of products of Dedekind η-functions and, for such a subclass of theories, we show analytically how misaligned supersymmetry is at work at any order of the Hardy-Ramanujan-Rademacher expansion and this allows us to prove that the state degeneracies vanish in an averaged sense

Summary

Introduction

Rate dominated by a factor eCeff n, with Ceff < Ctot, where Ctot is the inverse Hagedorn temperature. Two notable examples, which we discuss in what follows, are the non-supersymmetric heterotic SO(16)×SO(16)-theory [1, 2] and the open-string system made by an anti-Dp-brane on top of an Op-plane in type II string theory This second class of models provides a realization of the general phenomenon called “brane supersymmetry breaking” [3,4,5,6,7,8,9,10], studied in [11, 12] (see [13] for a recent review). This hints at a deeper connection that would substantially improve our understanding of non-supersymmetric type II string theory compactifications

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Discussion

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