The event will take place in King's Building, Strand Campus. Talks will take place at K2.31 (Nash Lecture Theatre). The reception and breaks will take place in the nearby River Room.
Schedule
10:00 - Tea and Coffee Reception
10:40 - Welcome address
10:45 - Franzini
11:30 - Retore
12:15 - Lunch break
14:00 - Capuozzo
14:45 - Coffee break
15:15 - Knighton
16:00 - Mann
Talks and Abstracts
Franzini: Free field realisation and zeta-function regularisation
Abstract: Free field realisation is a powerful tool, largely used in mathematical and theoretical physics, that allows the description of intricate symmetry algebras in terms of simple bosonic generators. An important example is the realisation of an affine Lie algebra in terms of a Heisenberg algebra, first proposed by Wakimoto and later generalised by Feigin and Frenkel. For any simple finite Lie algebra, this construction can be mathematically formulated as a vertex algebra homomorphism between the vacuum Verma module at critical level over the untwisted affine algebra and the Fock space for the beta-gamma system of free fields. Is it possible to generalise this construction when considering an untwisted affine algebra? In this talk, I will describe how the most naive approach leads to spaces that cannot be equipped with a vertex algebra structure and I will show possible ways to solve this issue. In particular, I will introduce a new vertex Lie algebra whose products depend on a formal parameter which plays the role of a regulator: this will enable us to identify the ill-defined quantities and ultimately to "renormalise'' them.
Retore: Two perspectives on elliptic deformations of AdS3xS3 S-matrices
Abstract: The presence of integrability in the context of AdS/CFT led to enormous progress
in the understanding of this gauge/gravity duality, while at the same time advancing integrability itself. Since then, integrable deformations of the original worksheet S-matrices were constructed both in AdS5 and in lower dimensional AdS backgrounds and led to interesting developments in both classical and quantum integrability. This talk will be dedicated to two new integrable elliptic deformations of the AdS3 S-matrix. The first is an exact deformation obtained from a purely integrability point of view, via the Boost automorphism mechanism. The second is the tree-level worldsheet S-matrix of an elliptically-deformed bosonic sigma model on AdS3xS3, computed in an attempt to give meaning to the first one.In this talk, we will explain the construction and the known properties of these two objects, and whether they are or not connected.
Capuozzo: An interpolating index for 4d N=2 superconformal field theories
Abstract: The preservation of rigid supersymmetries on curved manifolds can be analysed systematically by coupling to an appropriate off-shell supergravity multiplet. The sphere partition function of such theories computes a certain index, with fugacity refinements determined by the exact supergravity content to which the theory is coupled. In this talk, I will discuss ongoing work aimed at proving an equivalence between two such quantities: a particular instance of the superconformal index and the Ω-deformed, topologically twisted index of 4d N=2 SCFTs. I will then briefly discuss some implications of this equivalence, including its AdS/CFT dual realisation in terms of black hole microstates, as well as progress towards similar statements in other numbers of dimensions.
Knighton: Deriving the AdS/CFT correspondence from the path integral
Abstract: The AdS/CFT correspondence relates physical observables in string theory on AdS spacetimes to quantities calculated in ordinary quantum field theories. While this duality has been well-explored, the precise mechanism relating string theory to gauge theory quantities is poorly understood. We explain how such a dictionary works in the case of the AdS3/CFT2 correspondence, showing that the worldsheet path integral can be massaged in such a way that the dual field theory calculation becomes manifest.
Mann: AdS Three-Body Problem at Large Spin
Abstract: I will approach the computation of multi-twist anomalous dimensions in general CFTs from the perspective of a quantum N-body problem in AdS. After explaining how the balancing effects of AdS curvature and spin can make this problem tractable, I will derive an effective semi-classical description of the 3-body problem in the large-spin limit. Direct comparison with numerics shows that the Bohr-Sommerfeld quantization conditions are a good approximation for most states, in agreement with integrable examples from the planar limit of gauge theories. As an outlook, I will discuss the generalization to N>3. Based on joint work with Petr Krachuk.