10:00 - Torben Skrzypek (Imperial College)
Orbifolds of AdS/CFT - integrable yet defective
Abstract: Type IIB string theory on AdS_5 x S^5 is integrable, which allows us to compute the spectrum of the dual CFT to extreme accuracy, even for non-BPS states. The arguably simplest deformation of this model is an orbifold projection, which generically breaks supersymmetry but retains integrability. This allows us to study AdS/CFT in systems with reduced supersymmetry. If we break supersymmetry completely, as for example in type 0B theory, tachyons come to haunt us, and their matching across AdS/CFT is quite puzzling. If we retain N=2 supersymmetry, the gauge theory is well behaved and extensively studied. However, the string theory side is lagging behind, so I raise the question whether recent localisation results can help us understand it better.
11:00 - Emily Nardoni (IPMU)
Probing Anomalies of Non-Invertible Symmetries
't Hooft anomalies provide crucial insight into the properties of quantum field theories, imposing powerful constraints on their low energy dynamics. For invertible global symmetries, it is known that the 't Hooft anomalies can be characterized by an invertible TQFT in one higher dimension. In this talk we will discuss how the linking invariants in a non-invertible TQFT known as the Symmetry TFT can be used as a diagnostic for the anomalies of non-invertible symmetries. We will illustrate this proposal through examples in two and four dimensions, including 4d adjoint QCD, and comment on how knowledge of these anomalies can impose constraints on the dynamics.
18:30 - Emanuel Malek (Humboldt-Universität zu Berlin)
Computing anomalous dimensions of strongly-coupled CFTs with non-abelian global symmetries from supergravity
I will present a powerful new method that allows us to holographically compute the anomalous dimensions of strongly-coupled CFTs with non-abelian global symmetries. Key to this is a new way of constructing consistent truncations in supergravity using fibrations of coset spaces over a base, which are dual to such CFTs. I will show how, when the total space of the compactification has spherical topology, these compactifications can be described by a global generalised frame in Exceptional Field Theory. Using the recently-developed "Kaluza-Klein spectroscopy", this allows us to compute the full Kaluza-Klein spectrum of these backgrounds and hence the anomalous dimensions of local single-trace operators of the dual field theory. If time permits, I will speculate about going beyond spherical topologies.
10:00 - Colin Sterckx (ULB)
Type IIB S-folds and their deformations
We will review a recent application of Exceptional Field Theory: finding new families of solutions of Type IIB supergravity on AdS_4 x S^1 x S^5. These solutions provide certain limits of Type IIB S-folds, themselves dual to interfaces of SYM_4. Surprisingly, it is sometime possible to deform our new solutions and break all residual supersymmetry while preserving perturbative stability. We will present the geometric construction of such deformations which should be dual to non-supersymmetric conformal manifolds. We probed the non-perturbative stabilities of these solutions without finding any decay channel. This construction might provide counterexamples to the non-SUSY AdS swampland conjecture.
11:00 - Marija Tomasevic (Polytechnique)
Correspondence between rotating black holes and fundamental strings
The correspondence principle between strings and black holes is a general framework for matching black holes and massive states of fundamental strings at a point where their physical properties (such as mass, entropy, and temperature) smoothly agree with each other. This correspondence becomes puzzling when attempting to include rotation: At large enough spins, there exist degenerate string states that seemingly cannot be matched to any black hole. Conversely, there exist black holes with arbitrarily large spins that cannot correspond to any single-string state. We discuss in detail the properties of both types of objects and find that a correspondence that resolves the puzzles is possible by adding dynamical features and non-stationary configurations to the picture. Our scheme incorporates all black hole and string phases as part of the correspondence, save for one outlier which remains enigmatic: the near-extremal Kerr black hole. Along the way, we elaborate on general aspects of the correspondence that have not been emphasized before.
18:30 - Christoph Uhlemann (Oxford)
Splitting interfaces in 4d N=4 SYM
We discuss interface CFTs in which two 4d N=4 SYM CFTs are coupled at an interface which hosts 3d N=4 defect degrees of freedom. Focusing on the entanglement between the two half spaces to either side of the interface we show that the Ryu-Takayanagi prescription in general leads to multiple natural entanglement entropies, which we interpret as corresponding to different ways of assigning the 3d defect degrees of freedom to the two half spaces. We connect these results to recent discussions of universal relations for entanglement entropies in interface CFTs and to applications of double holography.
10:00 - Yolanda Lozano (Oviedo)
Low dimensional holography, defects and string dualities.
We will review the construction of various AdS3 and AdS2 solutions that find an interpretation as holographic duals of surface and line superconformal defects in higher dimensional, mother, SCFTs, involving 6d (1,0), 5d Sp(N) or 4d N=2 SCFTs. We will present explicit constructions in which the quiver field theories associated to these solutions are manifestly interpreted as the embedding of the defects onto the higher dimensional quivers associated to the mother SCFTs.
11:00 - Nikolay Bobev (Leuven)
Large N Partition Functions, Holography, and Black Holes
I will discuss the large N behavior of partition functions of the ABJM theory on compact Euclidean manifolds. I will pay particular attention to the S^3 free energy and the topologically twisted index for which I will present closed form expressions valid to all orders in the large N expansion. These results have important implications for holography and the microscopic entropy counting of AdS_4 black holes which I will discuss. I will also briefly discuss generalizations of these results to the superconformal index, as well as to other 3d SCFTs arising from M2-branes.
18:30 - Aaron Poole (Kyung Hee University)
Thermodynamics of accelerating AdS_4 black holes from the covariant phase space
There has been recent interest in accelerating black hole solutions of Einstein-Maxwell theory due to the remarkable property that they uplift smoothly into supergravity when the black hole horizon has the topology of a “spindle”. In this talk I will discuss the thermodynamics of accelerating black holes in AdS_4: I will explain how to generalize the allowed boundary conditions at conformal infinity in order to apply the covariant phase space formalism to such solutions. This will allow for a formal derivation of the conserved charges of the solution and a first law of accelerating black hole mechanics, improving upon previous forms of the law which contained ambiguities due to the lack of a well-posed variational problem. I will conclude with some applications of the first law when the black hole horizon is a spindle and comment on the nature of the supersymmetry and extremality conditions. This talk is based on https://arxiv.org/pdf/2306.16187.pdf in collaboration with Hyojoong Kim, Nakwoo Kim and Yein Lee.
10:00 - Adolfo Guarino (Oviedo)
New Janus/Hades solutions in M-theory
In this talk I will present new multi-parametric and analytic families of Janus/Hades solutions in M-theory dual to various classes of interfaces in ABJM3
11:00 - Lorenzo Bianchi (Torino):
Analytic bootstrap for magnetic impurities
We will discuss two classes of line defects in the O(N) critical model at the Wilson-Fisher fixed point. These extended excitations are relevant for condensed matter systems, such as doped quantum antiferromagnets. After reviewing some state-of-the-art analytic bootstrap techniques, we will apply them to compute the correlator of two bulk excitations at first order in the epsilon expansion. From this result we are able to extract an infinite set of defect CFT data.
18:30 - Christopher Rosen (Crete)
Super defects and supergravity
Spatially varying deformations of quantum field theories challenge our intuitions about renormalisation group flow, and offer new perspectives on physical systems with defects or boundaries. When such deformations preserve super(conformal) symmetries, they can be particularly amenable to study --this is especially true when viewed from the perspective of holographic duality.
I will review a series of recent results in the physics of supersymmetric theories deformed by spatially dependent couplings, or theories with "super defects". I emphasise the role of gauge/gravity duality in understanding these systems, and highlight interesting unexplored directions in this context.