List of Talks
Speaker: Kei Kaneda
Title: Seifert Manifolds in Quantum Gravity
Abstract: Seifert manifolds form an important class of three-manifolds. In recent years, they have attracted attention in three-dimensional pure quantum gravity, where they arise as a distinguished class of off-shell geometries. Seifert manifolds also include lens spaces, which play a role in the holographic relation between Abelian Chern–Simons theory and Narain-type conformal field theories. In this talk, I will review these two appearances of Seifert manifolds in quantum gravity. I will then outline an ongoing project that investigates how a consistent sum over Seifert manifolds might be formulated in Abelian Chern–Simons theory, focusing on the open questions rather than presenting definitive results.
Speaker: Giwan Kim
Title: Late-time OTOC in Toda theory from Moore-Seiberg data
Abstract: OTOC is a very useful measure of chaotic behaviors of a theory. Its late-time behavior can be derived from Moore-Seiberg data of a theory. Toda theory is a generalization of Liouville theory but its properties are only partially known compared to Liouville theory. In this talk, I will briefly review the concept of OTOC and related features of Liouville and Toda theory, and then I will introduce the Late-time OTOC computation of Liouville theory and its Toda generalization.
Speaker: Bufan Zheng
Title: An Introduction to Boundary Conformal Field Theory: Interfaces between the Ising and Tricritical Ising Models
Abstract: In this talk, I will first introduce two-dimensional boundary conformal field theory (BCFT), focusing on the consistency conditions that constrain conformal boundary conditions. I will then explain how BCFT techniques, together with the folding trick, provide a framework for studying and classifying conformal defects and interfaces. As a concrete application, I will consider conformal interfaces between the critical and tricritical Ising models. Motivated by Gaiotto’s proposal for the RG domain walls associated with flows between adjacent unitary minimal models, I will discuss how one may go beyond the RG interface and address the more general classification problem.
Speaker: Itsuki Hoshiba
Title: The Purely Cosmetic Surgery Conjecture and Quantum Invariants
Abstract: The purely cosmetic surgery conjecture asks whether distinct Dehn surgeries on a fixed knot can yield orientation-preservingly homeomorphic 3-manifolds. Meanwhile, quantum invariants of knots and 3-manifolds that have their origins in mathematical physics and are now also studied using algebraic and diagrammatic methods. In this talk, I will introduce the conjecture and quantum invariants, and discuss an approach to the conjecture using the Kontsevich invariant and the LMO invariant, which are two well-known quantum invariants
Speaker: Dongao Zhou
Title: Quantum Algebras from Holomorphic-Topological QFTs
Abstract: Quantum algebras (of Hopf type) have been found and studied extensively in various mathematical and physical literature such as link invariant, integrable models and supersymmetric gauge theories. Among all different physical realizations of quantum algebras, the one from holomorphic-topological QFTs show unique advantages as it organize the various properties of quantum algebras in an intuitive and computable way. This path is also expected to provide more insights on the interesting interaction between physics and mathematics around quantum algebras.
In this talk, I will first review some quantum algebras of interest and how they can be realized in holomorphic-topological QFTs from a universal perspective. After this, I will show how to construct cotangent Yangians from twisted N=2 supersymmetric gauge theories and explain some interesting aspects of this algebra.
Speaker: Kouki Kumagai
Title: Formulation of QFT via BV Formalism: From Constructing Correlation Functions to Deriving Operator Formalism
Abstract: In formulating a rigorous mathematical foundation for quantum field theory, it is crucial to establish a single framework capable of yielding both the path integral formalism and operator formalism. In this talk, we adopt K.Costello’s framework of Batalin-Vilkovisky (BV) formalism as this fundamental starting point, demonstrating how both formulations can be derived from it systematically.
Speaker: Yanming Su
Title: Monoidal category, module category and MPO
Abstract: I will introduce a method to build spin chain models equipped with certain symmetry using the symmetry category and its module category, together with the mathematical foundation of this formalism. I will focus on the case where the symmetry is described by the representation category of some finite group and talk more about the technical aspects in the study.
Speaker: Mengyang Zhang
Title: 3d SL(2,C) Chern-Simons theory, complex Liouville String and de Sitter Holography
Abstract: I will briefly review the relation between 3D Lorentzian de Sitter gravity and SL(2,C) Chern-Simons theory and show that the canonical quantization of CS theory leads to the Liouville CFT with complex central charge with the implications from standard dS/CFT correspondence. I will then review the recently developed complex Liouville strings with emphasis on its application to de Sitter gravity. In the end, I will comment on several new proposals on de Sitter holography from the observer's point of view.
Speaker: Victoria Venken
Title: Exploring cosmology in exotic corners of the string landscape
Abstract: It has proved incredibly difficult to find cosmologies with accelerated expansion, like our own universe, in the best-studied part of the string theory landscape.
At the same time, there are strange corners of the string theory landscape which have been far less explored and of which it is unclear if these corners make sense; for example the star-superstring theories. Surprisingly cosmic acceleration seems easy in these strange corners. Is it possible to better understand these corners and use them for cosmology?
Speaker: Aswin Parayil Mana
Title: Topological Phases and Generalized Symmetries from a Lattice Perspective
Abstract: In physics, phases of matter and their transitions are traditionally studied within Landau’s paradigm of symmetry breaking. However, not all phases of matter can be characterized in terms of conventional symmetry breaking. A prominent example is provided by topological phases of matter. In this talk, I will give a brief introduction to topological phases of matter from a lattice perspective. I will then discuss generalized symmetries and their applications to the study of topological phases. In particular, I will focus on the recently explored notion of non-invertible symmetries in lattice models. Finally, I will discuss symmetry-protected topological phases protected by non-invertible symmetries.
Speaker: Jiaxin Qiao
Title: Bootstrapping the Exceptional Virasoro Minimal Models
Abstract: The Virasoro minimal models admit the celebrated ADE classification, with the E6, E7, and E8 theories forming the exceptional families. While their spectra and modular invariants have been known for a long time, their full operator product data are considerably less explicit.
In this talk, I will describe a conformal-bootstrap approach to the E-series minimal models. After briefly reviewing the known results, I will formulate the crossing equations using the fusion kernels of Virasoro conformal blocks, which can be expressed in terms of quantum-group 6j symbols. A key simplification reduces the problem to a finite subsector. We solve the bootstrap equations in this subsector by computer for the E6, E7, and E8 series. I will then explain how this finite calculation leads to a solution of the full theory, and how one can establish the existence and uniqueness of the solution to the bootstrap equations, up to trivial sign redefinitions of local operators.
If time permits, I will also discuss the underlying symmetries of these models, including both ordinary symmetries and non-invertible symmetries.
Speaker: Vaibhav Gautam
Title: Quantum Simulations of Holographic Theories
Abstract: We advocate the sparsification of bosonic SYK models as a promising arena for the exploration of quantum advantage. We initiate the study of quantum simulations of the models, both in classical simulators and on quantum devices implemented using superconducting qubits. We point out subtleties in the quantum simulations of highly chaotic systems, which should be addressed in the future search for quantum advantage. I will comment on the ongoing attempt for a more bottom-up approach to a simulatable model with chaos. The talk is based on arXiv:2512.17294 with A. Matsuo and M. Yamazaki and upcoming work with N. Earnest-Noble and M. Yamazaki.
Speaker: Masataka Watanabe
Title: Effective field theory and vertex operator algebra
Abstract: I will talk about how effective field theory can capture the vertex operator algebra structure in superconformal theories in six, four and three dimensions.