In this talk we will investigate the Swampland Distance Conjecture in type IIB string theory compactified on K3 x T2. As conjectured one indeed finds a tower of exponentially light states using the Hodge-Deligne splitting of the middle homology in the degeneration limit. This tower, however, consists of quarter-BPS states, which can potentially decay into a pair of half-BPS states at walls of...

The Swampland Distance Conjecture (SDC) states that an infinite tower of modes becomes exponentially light when approaching a point at infinite distance in moduli space. At the large volume singularities of the Kähler moduli spaces of Calabi-Yau threefold compactifications, we use the monodromy matrices to explicitly construct the towers of states satisfying the SDC, which consist of charge...

The Swampland Distance Conjecture states that at infinite distance in the scalar moduli space an infinite tower of particles becomes exponentially massless. In the context of 4d Calabi-Yau compactifications we find that not only towers of particles, but also towers of strings and domain walls generally become tensionless at different infinite distance points. For $\mathcal{N}=1$ Calabi-Yau...

We investigate the swampland distance conjecture (SDC) in the complex moduli space of type II compactifications on one-parameter Calabi-Yau threefolds. This class of manifolds contains hundreds of examples and, in particular, a subset of 14 geometries with hypergeometric differential Picard-Fuchs operators. Of the four principal types of singularities that can occur — specified by their...

Demanding unitarity of correlators can put severe constraints on the allowed spectra of SCFTs. We discuss such constraints in the context of half-BPS operators in six dimensions using the conformal bootstrap and possible lower bounds on central charges one gets for theories with flavour. In particular we relate these bounds with results from F-theory and the size of its swampland.

We will consider the construction of 5d superconformal field theories by studying M-theory compactified on a non-compact Calabi--Yau threefold, which is related to the elliptically fibered Calabi--Yau threefold that, in F-theory, constructs the 6d SCFT that circle reduces to said 5d SCFT. We explain how many interesting features of 5d SCFTs, like flavour symmetry enhancement, arise from the...

I will argue that global 4d F-theory models generically exhibit holomorphic Yukawa matrices of higher rank. In a toy model, where one can explicitly compute all contributions to one type of couplings, the eigenvalues are shown to develop large hierarchies for generic complex structure moduli.

We present a systematic study of F-theory on smooth elliptic quotient threefolds. We show that general anomaly cancellation in the 6d SUGRA theory is satisfied upon the addition of additional discrete charged superconformal matter. The quotient generically also breaks the gauge symmetry to a discrete one. We use this method to study an order 6 example explicitly constructed via a quotient of a...

We consider compactifications of M-theory on 7-dimensional manifolds with G2 holonomy and focus on gauge theory sectors that are built as 3-manifolds of ADE singularities. We build novel gauge theory configurations that involve non-commuting normal deformations as well as gauge theory magnetic fluxes and provide methods to detect the presence of localised zero modes that can descend to chiral...

We analyze infrared consistency conditions of 3D and 4D effective field theories with massive scalars or fermions charged under multiple U(1) gauge fields. At low energies, one can integrate out the massive particles and thus obtain a one-loop effective action for the gauge fields. In the regime where charge-independent contributions to higher-derivative terms in the action are sufficiently...

The proposal for a new Swampland conjecture forbidding stable non-supersymmetric "locally AdS" warped throats, which generalizes the Swampland criterion forbidding stable non-supersymmetric AdS vacua, is discussed. The conjecture is motivated by the properties of systems of fractional D3-branes at singularities, and can be used to rule out large classes of warped throats with supersymmetry...

The KKLT scenario in a warped throat, if consistent, provides a concrete counterexample to both the AdS scale separation and the dS swampland conjectures. In this talk I will analyze the relevant effective field theory for the conifold modulus and the overall Kahler modulus that both have exponentially small masses. In particular, I will focus on KK modes that have masses below the mass scale...

This talk will be divided into two parts. In the first part, I focus on the attempt to construct effective axions with parametrically large decay constants in type IIB string models summarising work with A. Hebecker and D. Junghans (arXiv: 1812.05626). I argue that such axions can be realised as long winding trajectories in complex-structure moduli space by an appropriate flux choice. The...

The axion Weak Gravity Conjecture implies that when parametrically increasing axion decay constants, instantons corrections become increasingly important. In this talk I will discuss evidence for this statement, obtained by studying the couplings of axions that arise in Type IIA Calabi-Yau compactifications. To be more precise, I will discuss the asymptotic behavior of these couplings as one...

We consider geodesics of infinite length in the (classical) hypermultiplet moduli spaceof type II Calabi-Yau compactifications. When approaching such infinite distance points, a large amount of D-instantons develop an exponentially suppressed action ,substantially modifying the moduli space metric. In the corrected metric the path length becomes finite, although the metric at its endpoint...

Hitchin systems and Higgs bundles have recently been used to understand local aspects of M-theory compactifications on G2 manifolds. I will consider a similar approach from the heterotic point of view, using the heterotic/M-theory duality. Specifically, I will study alpha' corrections to the reduced heterotic system using the Hull-Strominger system. I will present some explicit solutions and...

It was shown that the majority of Weierstrass models in the 6D/4D F-theory landscape are non-minimal. Physically, these 6D/4D supergravity models are coupled to strongly coupled matter sectors, such as 6D (1,0) SCFTs and their compactifications. In this talk, I will focus on the particle spectrum of these sectors and their physical consequence.

My talk is a brief account of the increasing body of evidence that line bundle cohomology can be computed in terms of analytic formulae. Our experimental results include spaces such as complete intersections in products of projective spaces (in particular Calabi-Yau threefolds), toric varieties, hypersurfaces in toric varieties and del Pezzo surfaces. Machine learning plays an important role...

I will describe a large scale study of Calabi-Yau hypersurfaces in toric varieties. We construct large ensembles of O(10^7) Calabi Yau hypersurfaces and study key topological properties such as intersection numbers, cones of effective curves and divisors, and fibration structures. I will describe how the properties of a generic hypersurface scale with the Hodge numbers and discuss some of the...