Preprints 2022

Oneloop amplitudes in EinsteinYangMills from forward limits
Authors: Franziska Porkert, Oliver Schlotterer
Preprint number: UUITP04/22
We present a method to compute the integrands of oneloop EinsteinYangMills amplitudes for any number of external gauge and gravity multiplets. Our construction relies on the doublecopy structure of EinsteinYangMills as (super)YangMills with the socalled YM+phi^3 theory  pure YangMills coupled to biadjoint scalars  which we implement via oneloop CachazoHeYuan formulae. The YM+phi^3 building blocks are obtained from forward limits of treelevel input in external gluons and scalars, and we give the composition rules for any number of traces and orders in the couplings g and kappa. One the one hand, we spell out supersymmetry and dimensionagnostic relations that reduce loop integrands of EinsteinYangMills to those of pure gauge theories. On the other hand, we present fourpoint results for maximal and halfmaximal supersymmetry where all supersymmetry cancellations are exposed. In the halfmaximal case, we determine sixdimensional anomalies due to chiral hypermultiplets in the loop.

Gravitational waves in dark bubble cosmology
Authors: Ulf Danielsson, Daniel Panizo and Rob Tielemans
Preprint number: UUITP03/22
Abstract: In this paper we construct the 5D uplift of 4D gravitational waves in de Sitter cosmology for the brane world scenario based on a nucleated bubble in AdS5. This makes it possible to generalize the connection between the dark bubbles and Vilenkin's quantum cosmology to include gravitational perturbations. We also use the uplift to explain the interpretation of the apparently negative energy contributions in the 4D Einstein equations, which distinguish the dark bubble scenario from RandallSundrum.

Vanishing Yukawa Couplings and the Geometry of String Theory Models
Authors: L. B. Anderson, J. Gray, M. Larfors, M. Magill
Preprint number: UUITP02/22
Abstract: We provide an overview of recent work which aims to understand patterns of vanishing Yukawa couplings that arise in models of particle physics derived from string theory. These patterns are seemingly linked to a plethora of different geometrical structures and our understanding of the subject has yet to be consolidated in a unified framework. This short note is based upon a talk that was given by one of the authors at the Nankai Symposium on Mathematical Dialogues. Therefore it is aimed at a mathematical audience of mixed academic background.

Higher Symmetries of 5d Orbifold SCFTs
Authors: Michele Del Zotto, Jonathan J. Heckman, Shani Nadir Meynet, Robert Moscrop, Hao Y. Zhang
Preprint number: UUITP01/22
Abstract: We determine the higher symmetries of 5d SCFTs engineered from Mtheory on a C^{3}/Γ background for Γ a finite subgroup of SU(3). This resolves a longstanding question as to how to extract this data when the resulting singularity is nontoric (when Γ is nonabelian) and/or not isolated (when the action of Γ has fixed loci). The BPS states of the theory are encoded in a 1D quiver quantum mechanics gauge theory which determines the possible 1form and 2form symmetries. We also show that this same data can also be extracted by a direct computation of the corresponding defect group associated with the orbifold singularity. Both methods agree, and these computations do not rely on the existence of a resolution of the singularity. We also observe that when the geometry faithfully captures the global 0form symmetry, the abelianization of Γ detects a 2group structure (when present). As such, this establishes that all of this data is indeed intrinsic to the superconformal fixed point rather than being an emergent property of an IR gauge theory phase.