Title and Abstract
Wenbin Yan
Superconformal indices of N=4 Chern-Simons matter theories
Gaiotto and Witten found that one can construct 3d N=4 Chern-Simons matter theories by using N=4 SCFT whose momentum map of global symmetries satisfy special condition. Usually, one uses free hypermultiplet and twisted hypermultiplet, and more recently it was found that strongly coupled theory such as 3d version of T_N and Argyres-Douglas matter can also be used. In this talk, I will present results on superconformal indices of these N=4 theories and derive the Coulomb/Higgs limit. Our results can be used to determine the moduli space of vacua, check various interesting mirror symmetry involving CSM theory and usual N=4 gauge theories.
Xinyu Zhang
Quantum Symmetries in Four-dimensional Gauge Theories
In this talk, I will discuss hidden symmetries of four-dimensional gauge theories beyond the framework of group theory. A large class of N=2 superconformal field theories, which can be obtained from N=4 super Yang-Mills theory via orbifolding and then marginally deforming, enjoy a quantum deformation of the R-symmetry of the mother N=4 theory. The naively broken generators are not lost but upgraded to generators of a quantum groupoid, acting with a non-trivial co-product on a product of fields. We demonstrate that the Lagrangian is invariant and the spectrum organizes in representations of the quantum deformed SU(4) R-symmetry.
Zhenghao Zhong
Higgs branch RG flow via Decay and Fission
My talk will be on applying the Higgs mechanism to strongly coupled QFTs. To be more precise, I will look at Higgs branch RG flows between superconformal field theories with eight supercharges in spacetime dimensions d=3,4,5,6. I will introduce a new algorithm called the Decay and Fission of magnetic quivers which will give the Higgs branch phase diagram of these RG flows. This is based on our recent paper [arXiv:2401.08757] and proves to be a much more general and efficient approach than others in the literature.
Yunfeng Jiang
Some integrability perspectives on TTbar deformation
I will discuss some recent results on TTbar deformation from integrability. These include the application of form factor bootstrap program on the computation of correlation functions and integrable lattice regularization of integrable quantum field theories. For both topics, I will introduce the general background and then discuss the necessary modifications when we turn on TTbar deformation.
Rui-Dong Zhu
Quasinormal modes from connection formulae and collision limit
The quasinormal modes are an important class of characteristic physical quantities of black holes, and one straightforward way to compute them is to use the connection formulae. The connection formulae, however, in general are difficult to derive. In this talk, we provide supportive evidence to (i) the connection formulae obtained from 2d CFT reproduce the correct QNMs for differential equation with only regular singularities; (ii) the connection formulae for irregular singularities may be obtained by taking the collision limit appropriately.