UV Shadows in EFTs: Accidental Symmetries, Robustness and No-Scale Supergravity

TL;DR

This paper explores how accidental symmetries in string vacua lead to no-scale supergravities, analyzing quantum corrections, symmetry roles, and implications for de Sitter vacua in low-energy effective theories.

Contribution

It classifies nested no-scale supergravities, demonstrates how quantum corrections affect scale invariance, and connects higher-dimensional symmetries to 4D effective field theories.

Findings

Quantum corrections can break scale invariance while preserving some no-scale features.

The Kähler potential predictions match existing calculations at all perturbative orders.

p-form fields generate shift symmetries and relate 4D physics to higher-dimensional phenomena.

Abstract

We argue that accidental approximate scaling symmetries are robust predictions of weakly coupled string vacua, and show that their interplay with supersymmetry and other (generalised) internal symmetries underlies the ubiquitous appearance of no-scale supergravities in low-energy 4D EFTs. We identify 4 nested types of no-scale supergravities, and show how leading quantum corrections can break scale invariance while preserving some no-scale properties (including non-supersymmetric flat directions). We use these ideas to classify corrections to the low-energy 4D supergravity action in perturbative 10D string vacua, including both bulk and brane contributions. Our prediction for the K\"ahler potential at any fixed order in $\alpha'$ and string loops agrees with all extant calculations. p-form fields play two important roles: they spawn many (generalised) shift symmetries; and space-filling 4-forms teach 4D physics about higher-dimensional phenomena like flux quantisation. We argue that these robust symmetry arguments suffice to understand obstructions to finding classical de Sitter vacua, and suggest how to get around them in UV complete models.