# Conference Schedule

Talks in chronological order.

Speaker: Dieter Lüst
Title: Black Hole Entropy, Species Scales and Topological Strings
Abstract:
Slides

Speaker: Jake McNamara
Title: Cobordism and a Modified Gauss Law
Abstract: Gauge charges inside black holes may be detected by measuring the gauge flux at the horizon. In this talk, we discuss charges whose associated gauge flux is given by the cobordism class of the horizon manifold. We find that these charges satisfy a weaker version of Gauss’s Law: the net charge need only vanish on closed submanifolds with trivial normal bundles. Along the way, we identify a potentially severe domain wall issue in any particle physics model with spontaneously broken parity symmetry, such as the Nelson-Barr proposal for the Strong CP problem.
Slides

Speaker: Timo Weigand
Title: The Asymptotic Tower Weak Gravity Conjecture
Abstract: In its tower version, the Weak Gravity Conjecture (WGC) predicts infinitely many super-extremal states in every gauge theory coupled to quantum gravity. In this talk, we will explain how this conjecture is satisfied in M-theory compactified on Calabi-Yau threefolds for effective gauge theories that admit a weak coupling limit. Despite the absence of towers of super-extremal BPS states in many directions of the charge lattice, pointed out previously in the literature, the tower WGC is satisfied due to the existence of super-extremal non-BPS states whenever the gauge theory is connected to a weak coupling regime. This result rests on an interplay between the asymptotic geometry of the classical Kahler cone and aspects of state counting on Calabi-Yau threefolds, in particular Noether-Lefschetz theory and Donaldson-Thomas invariants.
Slides

Speaker: Thomas Grimm
Title: The Tameness of Quantum Field Theories
Abstract: Tame geometry originated in mathematical logic and implements strong finiteness properties by defining the notion of tame sets and functions. I briefly summarize the evidence that the tameness of a theory relies on its UV definition and can serve as a novel swampland principle. I then explain how to make the connection between quantum field theories and logical structures precise. This allows me to quantify our expectations on the tameness of the set of conformal field theories and its observables. I will end with some comments on how tameness allows one to implement a notion of finiteness of information.
Slides

Speaker: Craig Lawrie
Title:
a = c Theories and Emergent N = 4 from N = 1
Abstract:
I will consider 4d N = 1, 2 SCFTs obtained via the diagonal gauging of collections of non-Lagrangian Argyres–Douglas and conformal matter theories. Remarkably, many of these theories possess identical central charges: a = c, without any large N limit. In so doing, we discover a four-dimensional N = 1 supersymmetric field theory that is dual to N = 4 super Yang–Mills with gauge group SU(2n+1). The dual theory is constructed through the diagonal gauging of the SU(2n+1) flavor symmetry of three copies of a particular Argyres–Douglas theory. We find that this theory flows in the infrared to a strongly-coupled N = 1 SCFT that lies on the same conformal manifold as N = 4 SYM. We verify this duality by matching anomalies, the chiral operator spectrum, and the superconformal index.
Slides

Title:
Swampland program, extra dimensions and supersymmetry breaking
Abstract:

Slides

Speaker: Ibrahima Bah
Title: Non-invertible symmetry, holography and branes
Abstract: In this talk I will discuss some general methods for realizing topological symmetry generators in holography. In particular I will present a specific realization of non-invertible symmetry generators and their fusion rules in holographic duals of SU(N)/Z_N N=1 SYM. This will be both from a bottom-up perspective from an effective theory in AdS5, and from a top-down perspective in terms of D-branes in AdS5 backgrounds.
Slides

Speaker: Monica Kang
Title: 4d SCFTs in different guises: a 6d reveal
Abstract: When do two quantum field theories describe the same physics? I will discuss some approaches to this question in the context of superconformal field theories in four and six dimensions. Utilizing 4d class S theories that also admits 6d (1,0) SCFT origins, I will explain how certain class of 4d N=2 SCFTs, which a priori look like distinct theories, can be shown to describe the same physics, as they arise as torus-compactifications of identical 6d (1,0) SCFTs. Each 6d SCFT in question can be obtained from a parent 6d SCFT by Higgs branch renormalization group flow, and the parent theory possesses a discrete symmetry under which the relevant Higgs branch flows are exchanged. The existence of this discrete symmetry, which may be embedded in an enhanced continuous symmetry, proves that the original pair of class S theories are, in fact, isomorphic.
Slides

Speaker: Michele Del Zotto
Title: Uncharted Territories in Geometric Engineering
Abstract: Geometric engineering is the art of exploiting string/M/F theory on non-compact backgrounds to learn about quantum fields in various dimensions. In this talk I will present recent progress in this context on two apparently separate (but ultimately related) open problems. On the one hand, I will address the question of taking geometric engineering limits of Heterotic strings, which was recently solved for Du Val singularities in collaboration with Muyang Liu and Paul-Konstatin Oehlmann. On the other hand, I will present some new features arising when studying M-theory on singular G(2)-cones, which we found in the context of a project together with Bobby Acharya, Jonathan Heckman, Max Hübner and Ethan Torres. A connection between these two sides will be presented in the conclusions.
Slides

Speaker: Washington Taylor
Title: Progress and puzzles in the F-theory landscape
Abstract: This talk will report on some recent progress on studying the global structure of the 4D F-theory landscape, the associated distribution of rigid gauge groups, and natural realizations of Standard Model-like vacua; several related puzzles and open questions will also be discussed.
Slides

Speaker: Lara Anderson
Title: New Perspectives on Heterotic Conifold Transitions
Abstract: I will present new results on the geometry of Calabi-Yau conifold transitions as they arise in heterotic string compactifications. In particular, I will present particular classes of branes/bundles which can traverse the CY geometric transition in a controllable way. We use these observations to propose dualities for 5-branes and gauge bundles in heterotic conifolds which we then confirm at the level of spectrum in large classes of examples. While the 5-brane duality is novel, we observe that the bundle correspondence has appeared before in the Target Space Duality exhibited by (0,2) GLSMs. Thus our work provides a geometric explanation of (0,2) Target Space Duality.
Slides

Speaker: Jim Halverson
Title: Metric Flows and Calabi-Yau Metrics with Infinite-Width Neural Networks
Abstract: Neural networks provide state-of-the-art approximations of Calabi-Yau metrics. In this talk I’ll broaden these results and provide new understanding by utilizing advances in ML theory. Specifically, I will demonstrate that the dynamics of the NN-induced metric flow becomes increasingly tractable as the width of the network is taken to infinity. In the strict infinite limit, a new duality frame known as frozen NTK regression opens up that allows for inclusion of famous metric flows. For instance, Perelman’s formulation of Ricci flow is a particular local metric flow at infinite width. I will then modify the general analysis to the case of Kahler metric flows, and present preliminary results of infinite-width approximations of Calabi-Yau metrics, if time permits.
Slides

Speaker: Patrick Jefferson
Title: New tools for analyzing non-perturbative superpotentials in 4D string vacua
Abstract: A promising strategy for stabilizing Kähler moduli in 4D type IIB string compactifications on Calabi-Yau orientifolds involves the non-perturbative superpotential generated by D3-instantons or D7 gaugino condensation. Since these vacua admit a dual description as F/M-theory on an elliptic Calabi-Yau fourfold, the nonperturbative superpotential can be seen as being generated by M5-instantons wrapping “vertical” supersymmetric 6-cycles in the internal space that satisfy particular topological conditions. In this talk I present a novel method for determining the Hodge structure of these supersymmetric 6-cycles that does not require a complete specification of the F/M-theory uplift; this in turn provides valuable information about the non-perturbative superpotentials for a large set of type IIB string vacua. Key technical results include novel combinatorial formulae for the Hodge numbers of prime toric divisors in O7/O3 orientifolds of Calabi-Yau toric hypersurfaces, along with a conjectural expression for the Euler characteristic that exhibits the contributions from terminal singularities associated to O3-planes. Based on 2211.00210 and w.i.p. with Manki Kim (MIT).
Slides

Speaker: Ben Heidenreich
Title: Swampland and Geometry in 5d
Abstract: I present the results of strenuous tests of the (sub)lattice Weak Gravity Conjecture (WGC) recently carried out in a large class of 5d theories arising from M-theory compactified on a Calabi-Yau threefold. Reconstructing the birationally-extended Kähler moduli space using the Gopakumar-Vafa invariants, we identify the cone of BPS black holes and verify that there is a BPS particle at every lattice site within it, up to a cutoff set by the available computing power. These checks, successfully carried out for thousands of geometries, are not limited to weak-coupling / asymptotic limits nor to towers of exponentially-light particles. Examining such limits more closely uncovers a rich interplay with the particle/string (sub)lattice WGC, the Distance Conjecture, and a form of finiteness encoded in (close relatives of) the Kawamata-Morrison cone conjecture, as well as a novel description of the cone of effective divisors of a Calabi-Yau threefold.
Slides

Speaker: Miguel Montero
Title: The Chronicles of IIBordia Part I: Branes from the Abyss
Abstract: In this talk I will review the cobordism conjecture of McNamara & Vafa and explain how it can be used to predict new objects in quantum gravity. I will illustrate this with a somewhat detailed analysis of a new non-supersymmetric brane of IIB string theory, and connect it with a discussion of discrete theta angles in IIB string theory, as well as the recent discovery of a new component of moduli space with 16 supercharges. This will then tie in with Markus Dierigl’s talk, where all other cobordism groups of IIB and the corresponding branes are discussed more systematically.
Slides

Speaker: Markus Dierigl
Title: The Chronicles of IIBordia – Part II: The Rise of Metaplectia
Abstract: In this talk I will extend the analysis of the Cobordism Conjecture in type IIB string theory from 7-branes, to lower-dimensional setups. We will re-discover several interesting F-theory backgrounds including non-Higgsable clusters and S-fold geometries. Moreover, there are some new interesting configurations that can contain reflection 7-branes, discussed in Miguel Montero’s talk. If time permits I will also discuss anomalies of the duality action.
Slides

Speaker: Max Hübner
Title: The Branes Behind Duality Defects
Abstract: Branes wrapped on ‘cycles at infinity’ in a string theory construction give generalized symmetry operators in the engineered field theory. We briefly review this construction and consider it more closely in the context of field theories engineered via D3-brane probes of Calabi-Yau threefolds. In this setting we argue that 7-branes wrapped on the boundary of the Calabi-Yau construct duality defects for the D3 world volume theory.
Slides

Speaker: Cumrun Vafa
Title: Bounds on the Species Scale and the Distance Conjecture
Abstract:
Slides

Speaker: Tom Rudelius
Title: Sharpening the Distance Conjecture in Diverse Dimensions
Abstract: The Distance Conjecture holds that any infinite-distance limit in the scalar field moduli space of a consistent theory of quantum gravity must be accompanied by a tower of light particles whose masses scale exponentially with proper field distance $||\phi||$ as $m \sim \exp(- \lambda ||\phi||)$, where $\lambda$ is order-one in Planck units. While the evidence for this conjecture is formidable, there is at present no consensus on which values of $\lambda$ are allowed. In this talk, I will propose a sharp lower bound on $\lambda$ in $d$ spacetime dimensions: $\lambda \geq 1/\sqrt{d-2}$. I will provide several lines of evidence for this bound and briefly discuss its implications for scalar field potentials and cosmology.
Slides

Speaker: Iñaki García Etxebarria
Title: Branes and symmetries for N=3 SCFTs
Abstract: I will explain how to derive various results about the generalised symmetry structure of N=3 and N=4 S-fold SCFTs using holography. The new results in the N=3 case include the spectrum of 1-form symmetries, their ‘t Hooft anomalies, and the existence of non-invertible symmetries for appropriate choices of global form.
Slides

Speaker: Muyang Liu
Title: Back to Heterotic ALE Instantonic Little String Theories
Abstract: We revisit the properties of Heterotic string compactifications on ALE space in a series of our recent (upcoming) publications. This project is primarily motivated by recent advances in comprehending the structures of six-dimensional theories and their continuous 2-group symmetries. So far, instantonic heterotic E8 × E8 theories are rarely visited due to the lack of the Lagrangian description, with the exceptions explored by Aspinwall and Morrison. I will present the construction of novel Heterotic E8 × E8 ALE instantonic theories using the 6d conformal matter approach, therefore extend previous results in the literature. They are predicted as T-dual partner with the known Spin(32)/Z2 ALE instantonic LSTs through the matching criteria associated with the Coulomb and tensor branch data. In particular, these predictions are proven by utilizing the geometric engineering in F-theory, where the T-dual system is realized as the inequivalent elliptic fibration structure of the same geometry. Note that the elliptic fibered Calabi-Yau in our consideration admits a nested elliptic K3 fibration structure. This is crucial to our design: the underlying K3 determine the flavor groups and their global forms, serving as the key to identify various T-dualities. This leads to more generic LSTs originating from non-geometric Heterotic backgrounds: for instance, a particularly exotic class of LSTs formed from inequivalent elliptic fibrations of the extremal K3. In the end, the architecture also inspires us to investigate the geometric engineering limit of heterotic strings in ALE space.
Slides

Speaker: Ling Lin
Title: Generalized symmetries and frozen singularities
Abstract: I will revisit string and M-theory compactifications on frozen singularities, and discuss their higher-form symmetries. I will also elaborate on the connection to the phenomenon of decomposition in the presence of (d-1)-form symmetries.
Slides

Speaker: Sakura Schäfer-Nameki
Title: Geometric Engineering and Categorical Symmetries
Abstract:
Slides

Speaker: Fabio Apruzzi
Title: Generalized quotients and holographic duals for 5d S-fold SCFTs
Abstract: S-folds of 5d SCFTs, including T_N, leads to brane webs with E_{7,8,9} 7-branes. I will first describe how to generalize the construction to `fractional quotients’, which are based on S-fold actions linking multiple copies of the seed theory and lead to H_{0,1,2} 7-branes. I will then focus on the holographic dual solutions for both classes. This expands the space of explicitly known Type IIB AdS_6 solutions by incorporating F-theory 7-branes of type E_{7,8,9} and H_{0,1,2}, extending previous constructions for O7-planes. Finally I will present some computed observables including the free energies and link the results to matrix model descriptions.
Slides

Speaker: Saghar Hosseini
Title: Symmetries and self-dual fields in string theory
Abstract: An important recent realisation is that the classification of symmetries and their anomalies in a given QFT may be characterised in one higher dimension by a symmetry topological field theory (SymTFT) via inflow mechanics. Such descriptions can naturally emerge whenever we can construct quantum field theories from string theory or M-theory. In this talk, I will discuss how to construct the BF theory in SymTFT from geometry.
Slides

Speaker: Jacques Distler
Title: VOAs and RG Flows between d=4, N=2 SCFTs
Abstract: There is a rich structure of Renormalization Group flows between 4d N=2 SCFTs. I will summarize some recent work understanding the properties of these flows from the perspective of the associated 2d VOAs.
Slides

Slides

Speaker: Rafael Álvarez-García
Title: Open-Moduli Infinite-Distance Limits in Six-Dimensional F-Theory
Abstract: We analyze infinite-distance limits in the complex structure moduli space of six-dimensional F-theory, giving an algebro-geometric classification and a physical interpretation. From the point of view of the Swampland Program, the motivation is to understand the fate of open-moduli infinite-distance limits in relation with the Distance Conjecture. From an F-theory perspective, the infinite distance limits correspond to suitable non-minimal singularities in codimension one and higher. While codimension-two finite-distance non-minimal singularities have been understood as SCFT’s in a major classification effort, the goal of our analysis is to elucidate the meaning of the infinite-distance codimension-one and codimension-two non-minimal singularities. We argue why the limits over $\mathbb{P}^{1}$-fibered bases are a natural starting point for the detailed analysis, and comment on preliminary results showing that they are decompactification limits in a dual sense.

Speaker: Dewi Gould
Title: Aspects of Symmetries from Branes
Abstract: I will present some work in progress in collaboration with Fabio Apruzzi, Federico Bonetti and Sakura Schafer-Nameki on understanding symmetries using branes. It has recently been explained that topological generalised symmetry generators can have stringy origins as branes placed “at infinity”. We probe this idea in a range of holographic contexts and study fusion rules, the action of symmetry generators on charged objects, and other interesting symmetry features using brane physics.

Speaker: Ruiwen Ouyang
Title: Gauge and Yukawa Unification in Grand Unified Theories
Abstract:  In my talk, I will roughly mention my past work about the unification of Yukawa couplings in SO(10). I will also discuss some potentially promising prospects in phenomenology, like the family unification in GUTs, the exploration of generalized symmetries in GUTs, and the application of Swamplands constraints in beyond the standard model (BSM) model building.

Speaker: Enoch Leung
Title: (Stringy) Time-Reversal Defects at Rational 𝜃-Angles in 4d SU(M) Yang-Mills Theory
Abstract: Recently it was discovered that 4d Maxwell theory and massive QED have a (non-invertible) time-reversal symmetry at rational 𝜃-angles. We observe that one may arrive at an analogous conclusion for SU(M) (super-)Yang-Mills theory using a certain combination of stringy probes in the Klebanov-Strassler solution in Type IIB string theory.

Title: Condensate Defects from Tachyon Condensation
Abstract: In the last couple years there have been many investigations using string theoretic constructions to probe generalized symmetries in quantum field theory; an interesting development on this front has been the identification of non-invertible symmetry defects arising from Dp-brane actions in Type II backgrounds. A plausible understanding of the fusion itself is to view the condensate defect as arising from a dynamical stringy process: tachyon condensation.

Speaker: Muldrow Etheredge
Title: Branes and Symmetries for N=3 S-folds
Abstract:  4d N=3 theories are non-Lagrangian theories that were discovered in 2015 and constructed using “S-folds”. In this talk, I discuss how holography can be used to predict the higher-form symmetries of these theories

Speaker: Ethan Torres
Title: Conformal Interfaces of 5D SCFTs from G2 Orbifolds
Abstract:  Thanks to R. Bryant and S. Salamon, one can write down complete G2 metrics on cones over CP^3 and SU(3)/U(1)^2. The physics of these spaces as backgrounds in M-theory is fairly simple, especially considering that there are no instanton corrections to the geometry. However, there exists a vast landscape of orbifold quotients of these G2 manifolds, and thus, just as much 4D N=1 physics left to uncover. I will mention why these 4D N=1 theories are very often conformal interfaces inside 5D SCFTs which cannot be fully decoupled from the 5D bulk. I will also highlight a procedure to read off global symmetries of the 5D SCFTs and to what extent they are inherited by the 4D interface theory. Based on upcoming work with B. Acharya, M. Del Zotto, J.J. Heckman, and M. Hübner.

Speaker: Xingyang Yu
Title: Non-invertible Symmetries of 2D Gauge Theories from IIB String Theory
Abstract:  I will briefly discuss generalized global symmetries of 2D gauge theories on D1-branes probing Calabi-Yau 4-fold singularities. The 3D symmetry TFTs for these theories can be derived via the dimensional reduction from IIB string theory, from which we can read the branes behind charged and symmetry operators. I’ll also discuss realizing non-invertible symmetries by gauging global symmetries with mixed anomalies analogous to the KOZ construction in 4D QFTs.

Speaker: Hao Zhang
Title: M-theory frozen singularities in 7d: orthogonalization map
Abstract: To supplement the preceding talk on M-theory frozen singularities in 7D, we present an interesting formulation of our “local freezing map” using (co)marks of DE-type affine Dynkin diagrams