Poster Session
Time: 15:30–18:00 on March 4th.
Poster List
- Composite operators in N = 4 Super Yang-Mills — Anastasiia Novikova
- Bootstrapping multipoint defect correlators — Andrea Mattiello
- EE in Janus — Ankit Anand
- Shape Deformations of the Sphere in Pseudo-Entropy and dS/CFT — Avijit Das
- Cobordism walls for 10d string theories from supercritical dimensions — Chuying Wang
- Bootstrapping Gukov-Witten defects in N=4 SYM — Davide Bonomi
- Effective field theory for dissipative photons from higher-form symmetries — Genki Yoshimura
- Gauging fermionic 2-group symmetry — Hao Xu
- Entanglement Spectrum Resolved by Loop Symmetries — Haruki Yagi
- Indecomposability in non-Hermitian conformal field theory — Iao-Fai Io
- Entanglement entropy and conformal bounds for d = 5 CFTs — Javier Moreno
- Domain Walls in Large-N QCD3 — Jonathan J. Whittle
- Effective string theory on a torus: the 3d Ising domain wall — José Matos
- CFT with multiple boundaries — Joseph Dominicus Lap
- Particle-soliton Degeneracy in Deformed Yang-Mills Theory — Jun Maeda
- Non-invertible symmetries on a tensor product Hilbert space in 1+1 dimensions — Kansei Inamura
- Quantum teleportation between holographic CFTs — Liang Li
- Topological Aspects of Type IIB Superstring Theory — Masashi Kawahira
- the W_3 classical blocks with semi-degenerate operators — Mikhail Pavlov
- Schwinger-Keldysh approach to tunneling transport at a hadron-quark interface — Motoi Tachibana
- Semi-Abelian theory with the modified Villain lattice — Nagare Katayama
- Categorical Continuous Symmetries — Ran Luo
- Horizon structures and extremal limits of Reissner-Nordström black holes in Weyl conformal gravity — Reinosuke Kusano
- Protected Interface Modes in Symmetry-Enriched CFTs — Saranesh Prembabu
- Entanglement structure of (1+1)-d boundary CFT — Shuma Nakashiba
- Symmetry Spans and Enforced Gaplessness — Takamasa Ando
- The application of ZX-calculus in non-invertible symmetries — Yanming Su
- Complex Conformal Field Theories in the Two-Dimensional Potts Model: Bulk and Boundary Perspectives — Yin Tang
- Extension, substructure and domain wall: Fusion ring-based classification of CFTs and TQFTs — Yoshiki Fukusumi
- Exotic theta terms in 2+1d fractonic field theory — Yuki Furukawa
1. Composite operators in N = 4 Super Yang-Mills
Speaker: Anastasiia Novikova
Abstract:
We study multi-particle operators in N = 4 Super Yang–Mills theory at strong ’t Hooft coupling, focusing on the poorly understood regime of triple-trace operators. While partial information exists from correlation function studies, no controlled or systematic results for these higher-trace operators are currently available. Using Hamiltonian methods in AdS, we obtain direct access to their low-twist spectrum. We present the structure of three- and higher-particle states and discuss the implications for spectral statistics and chaotic behavior.
2. Bootstrapping multipoint defect correlators
Speaker: Andrea Mattiello
Abstract:
We study multipoint correlation functions in defect CFTs, focusing for example on the bulk–bulk–defect three-point function of scalar operators. Working in the lightcone limit where one bulk operator becomes null-separated from the other bulk insertion, we obtain explicit expressions for the corresponding bulk conformal blocks in terms of Lauricella hypergeometric functions. Analyzing this limit reveals structural features of multipoint defect correlators and clarifies how bulk and defect kinematics interact in the lightcone regime. Combined with the known form of defect conformal blocks, these results open a route for applying the conformal bootstrap to extract previously unexplored defect CFT data. Finally, our formalism can be specialized to holographic examples — for instance, four-dimensional N=4 SYM with a Wilson-line defect — where it may be used to compare analytic and holographic predictions.
3. EE in Janus
Speaker: Ankit Anand
Abstract:
We discuss the holographic entanglement entropy in Janus deformed AdS$_3$ geometries.
4. Shape Deformations of the Sphere in Pseudo-Entropy and dS/CFT
Speaker: Avijit Das
Abstract:
We investigate pseudo-entropy in non-unitary Euclidean CFTs within the framework of the dS/CFT correspondence, extending recent studies that revealed connections to timelike holographic entanglement entropy in AdS/CFT. Geometric probes such as Ryu–Takayanagi (RT) surfaces in the mixed Euclidean–Lorentzian de Sitter patch have been used to encode holographic information at future conformal infinity, but analyses so far have focused solely on ball-shaped entangling regions.
Here, we compute the contribution to the universal part of the pseudo-entropy in dS₄/CFT₃ arising from Fourier deformations about the spherical case. To isolate this universal term, we apply a covariant Conformal Renormalization scheme based on embedding Einstein gravity into Conformal Gravity and exploiting the link between renormalized area and the codimension-2 conformal Graham–Witten anomaly.
Our results identify the C_T coefficient of the non-unitary CFT, paralleling shape-deformation analyses in AdS, and reveal non-unitarity signatures reminiscent of environmental interactions in open quantum systems, hinting at new physics in de Sitter holography.
5. Cobordism walls for 10d string theories from supercritical dimensions
Speaker: Chuying Wang
Abstract:
The Swampland Cobordism Conjecture conjectured the existence of a domain wall configuration connecting any two quantum gravity theories. Within the framework of supercritical string theory, a unified description of type 0A/0B, type IIA/IIB, and their corresponding domain walls can be argued to exist. The spacetime and worldsheet explicit descriptions of these GSO domain walls are studied in our work. Furthermore, we also exploit this description to construct higher codimension non-perturbative topological defects.
6. Bootstrapping Gukov-Witten defects in N=4 SYM
Speaker: Davide Bonomi
Abstract:
I will discuss Gukov-Witten surface defects in N=4 Super Yang-Mills from the point of view of the analytic conformal bootstrap. These defects are defined by the singular behaviour of the gauge and scalar fields along a surface. After reviewing a recently derived conformal dispersion relation, I will show how to bootstrap the two-point functions of bulk operators in presence of a surface defect.
7. Effective field theory for dissipative photons from higher-form symmetries
Speaker: Genki Yoshimura
Abstract:
Symmetry provides a powerful guiding principle in theoretical physics.
Effective field theories based on global symmetries and their patterns of spontaneous breaking have been remarkably successful in capturing universal long-wavelength dynamics. This framework can be further refined using generalized global symmetries, for instance higher-form symmetries.
Electromagnetism in vacuum is a well-known example of spontaneous breaking of a U(1) 1-form symmetry, with the photon emerging as the associated Nambu–Goldstone mode. However, the behavior of photons in this broken phase at finite temperature, i.e. photons in the insulator, has not been studied from the perspective of the U(1) 1-form symmetry.
Building on this symmetry structure, we construct an effective field theory that incorporates fluctuations and dissipation beyond purely Hermitian dynamics, formulated within the Schwinger–Keldysh formalism.
Our theory provides a model-independent description of dissipative photon dynamics, identifying higher-form symmetry as the organizing principle of their effective time-evolution.
8. Gauging fermionic 2-group symmetry
Speaker: Hao Xu
Abstract:
By Deligne’s celebrated theorem, any symmetric fusion category is equivalent to the category of super-representations of a finite supergroup. More concretely, this finite supergroup can be reconstructed as the group of tensor automorphisms of a chosen fiber functor to the category of super vector spaces. Recent developments have extended this perspective to the categorified setting of symmetric fusion 2-categories. In particular, Décoppet and Yu have shown that every symmetric fusion 2-category admits a fiber 2-functor to \mathbf{2sVec}. From a physical viewpoint, one can “ungauge’’ this fiber 2-functor to obtain a finite super 2-group. In ongoing work with Zhi-Hao Zhang (BIMSA), we aim to give an explicit description of these fermionic 2-group symmetries and to highlight the hidden richness of data that is invisible at the decategorified level.
9. Entanglement Spectrum Resolved by Loop Symmetries
Speaker: Haruki Yagi
Abstract:
A rigorous analysis is presented for the entanglement spectrum of quantum many-body states possessing a higher-form group-representation symmetry generated by topological Wilson loops, which is generally non-invertible. A general framework based on elementary algebraic topology and category theory is developed to determine the block structure of reduced density matrices for arbitrary bipartite manifolds on which the states are defined. Within this framework, we scrutinize the impact of topology on the entanglement structure for low-dimensional manifolds, including especially the torus, the Klein bottle, and lens spaces. By further incorporating gauge invariance, we refine our framework to determine the entanglement structure for topological gauge theories in arbitrary dimensions. In particular, in two dimensions, it is shown for the Kitaev quantum double model that not only the topological entanglement entropy can be reproduced, but also the Li-Haldane conjecture concerning the full entanglement spectrum holds exactly.
10. Indecomposability in non-Hermitian conformal field theory
Speaker: Iao-Fai Io
Abstract:
Logarithmic conformal field theory (LCFT) describes critical phenomena in non-Hermitian systems. In this work, we study a (1+1)D non-Hermitian massless free-fermion field theory and confirm its conformal invariance. We construct an infinite set of operators that satisfy the Virasoro algebra and identify the central charge c = −2. The spectrum of this model exhibits an indecomposable Jordan-cell structure, indicating that it is an LCFT. We compute the indecomposability parameters β at the first two levels and find that they coincide with those of the symplectic fermion theory, suggesting a close connection between the two theories.
11. Entanglement entropy and conformal bounds for d = 5 CFTs
Speaker: Javier Moreno
Abstract:
In this talk, we will discuss how to rigorously define the finite contribution to the entanglement entropy of five-dimensional conformal field theories. To do so, we employ mutual information, a UV-finite quantity whose definition involves introducing a controlled geometric interface—a small separation between entangling surfaces that serves as a physical regulator. The expansion of mutual information across this regulated interface isolates the universal CFT data while keeping all divergences manifestly under control. We will present explicit computations within the extended mutual information framework. Finally, we will explore whether the entanglement-entropy bounds known in three and four dimensions can be consistently extended to five-dimensional conformal field theories, examining in detail the limiting cases of the ball-shaped and strip-like entangling regions.
12. Domain Walls in Large-N QCD3
Speaker: Jonathan J. Whittle
Abstract:
In the Large-N limit QCD3 is known to possess a series of degenerate vacua. The domain walls interpolating between them admit multiple different descriptions including a holographic setup in terms of branes, each of which offers different viewpoints into the structure and properties of these walls.
13. Effective string theory on a torus: the 3d Ising domain wall
Speaker: José Matos
Abstract:
We use effective string theory (EST) to compute the thermodynamic properties of a toroidal 2d domain wall embedded in a 3d torus. We test our predictions in the 3d Ising model with anti-periodic boundary conditions, using a two-step flat-histogram Monte Carlo method in an ensemble over the boundary coupling that delivers high-precision free energy data. The predictions from EST reproduce the lattice results with only two adjustable parameters: the string tension and the leading Wilson coefficient.
14. CFT with multiple boundaries
Speaker: Joseph Dominicus Lap
Abstract:
CFTs with 1 or 2 boundaries have been explored for over 2 decades, but what about for 3 or more? One might expect that the moduli space grows rather quickly and the problem soon becomes intractable. I will show this is not always the case and that the additional scales can encode some interesting physics.
15. Particle-soliton Degeneracy in Deformed Yang-Mills Theory
Speaker: Jun Maeda
Abstract:
We explore particle-soliton degeneracy in higher-dimensional quantum field theories. As a concrete example, we analyze deformed PSU(N) Yang-Mills theory at θ=π, where semiclassical methods are under reliable control.
16. Non-invertible symmetries on a tensor product Hilbert space in 1+1 dimensions
Speaker: Kansei Inamura
Abstract:
I will introduce an index of non-invertible symmetry operators in 1+1 dimensions and discuss its relation to the realizability of non-invertible symmetries on the tensor product of finite dimensional on-site Hilbert spaces on the lattice. Our index generalizes the Gross-Nesme-Vogts-Werner index of quantum cellular automata (QCAs). Assuming that all fusion channels have the same index, I will show that the fusion rules of finitely many symmetry operators on a tensor product Hilbert space can agree, up to QCAs, only with those of weakly integral fusion categories. I will also show that the fusion category symmetries must be integral if the fusion rules mix only with QCAs with the trivial index, reproducing a recent mathematical result of Evans and Jones. This presentation will be based on arXiv:2602.12053.
17. Quantum teleportation between holographic CFTs
Speaker: Liang Li
Abstract:
We study how energy and quantum entanglement are transferred when two identical CFTs are entangled locally. This is probed by considering a local operator insertion in one of the CFTs. When the CFTs have holographic duals via the AdS/CFT correspondence, the transfer happens through an AdS wormhole that allows signal propagation even beyond the horizon from one AdS boundary to the other; we demonstrate this in explicit CFT calculations. We argue that this transmission is possible because the insertion of a local operator is not a unitary process but a regularized version of projection measurement, and that this is interpreted as quantum teleportation. We also find that this leads to a phenomenon opposite to scrambling, where mutual information, instead of being suppressed, gets enhanced by the insertion of a local operator excitation.
18. Topological Aspects of Type IIB Superstring Theory
Speaker: Masashi Kawahira
Abstract:
Type IIB superstring theory is important for phenomenology and cosmology because it contains GUT-like structures and accommodates de Sitter scenarios. However, it yields a large number of vacua, which makes observational predictions difficult.
In this talk, we show an exact result for IR theories arising from Type IIB superstring theory. Interestingly, this result is independent of the choice of vacuum.
19. the W_3 classical blocks with semi-degenerate operators
Speaker: Mikhail Pavlov
Abstract:
We consider 4-point W_3 classical blocks focusing on the blocks level-1 and level-2 semi-degenerate operators. We derive BPZ-type equations for the auxiliary 5-point blocks with one additional fully degenerate operator. The monodromy properties of these equations are encoded by the accessory parameters, related to the 4-point W_3 classical blocks. We solve the BPZ-type equations via heavy-light perturbation theory and find the accessory parameters, which allows us to obtain the explicit expressions for the considered class of classical blocks.
20. Schwinger-Keldysh approach to tunneling transport at a hadron-quark interface
Speaker: Motoi Tachibana
Abstract:
We theoretically discuss quantum tunneling transport and frictions at a hadron-quark matter interface based on the Schwinger-Keldysh approach combined with the tunneling Hamiltonian, which has been developed in the context of condensed matter physics. In the inner core of massive neutron stars, it is expected that cold quark matter appears at sufficiently high densities and hence exhibits color superconductivity, surrounded by nucleon superfluids at lower densities. The perturbative expressions of the tunneling current and the friction at the interface are obtained in terms of the non-equilibrium Green's functions. We demonstrate the DC Josephson current that occurs at the hadron-quark superfluid interface in the present scheme. Our framework can be applied to various conflagrations involving the interfaces relevant to astrophysical phenomena.
21. Semi-Abelian theory with the modified Villain lattice
Speaker: Nagare Katayama
Abstract:
We construct the semi-abelian gauge theory with the modified Villain lattice by applying the techniques of gauging Charge Conjugation on the lattice, which is proposed by Theodore Jacobson. Also, we study the symmetry, duality, and the anomaly on the lattice.
In addition, we use these facts to extend the 2d Cardy-Rabinovici model. The original CR model has both the theta-periodicity and duality, but not have all the possible gapped phases for the electric ZN × ZN symmetry. Therefore we discuss whether the semi-abelianized CR model can realize an exotic gapped phase, which is not realized in the original CR model.
23. Categorical Continuous Symmetries
Speaker: Ran Luo
Abstract:
Previous studies of generalized global symmetries has long craved for a categorical framework for continuous symmetries, which are imperative for almost all QFTs. In our work [2509.13170], we have proposed a construction for Lie group symmetry category in (1+1)d as the category of skyscraper sheaves, Sky^{\tau}(G), with possible anomaly \tau. We have also proposed that its 2+1d SymTFT is described by the Drinfeld center. We explicitly calculate the modular data of SymTFT for U(1) symmetry with anomaly, and also the non-abelian case of SU(2) symmetry.
24. Horizon structures and extremal limits of Reissner-Nordström black holes in Weyl conformal gravity
Speaker: Reinosuke Kusano
Abstract:
We present recent results from a study of dyonic Reissner-Nordström black hole spacetimes in Weyl’s conformal fourth-order theory of gravity. We obtain the extremal limits of both metrics as functions of the standard conformal gravity parameters $\beta$, $\gamma$, and $\kappa$, and map the full extent of positive-mass spacetimes. We find that due to the innermost horizon not necessarily being a Cauchy horizon, we may obtain a so-called “nested black hole” structure, by which we denote a Schwarzschild-esque black hole inside another Schwarzschild-anti-de Sitter black hole. Also, in addition to a complete review of positive mass spacetimes, we obtain a critical charge value for which three horizons collide. We further find that these triple-horizon-mergers may come in two varieties; one where the Cauchy, event, and cosmological horizons collide, and the second variety (unobtainable in general relativity) in which an inner event horizon, intermediate Cauchy collide, and outer event horizon collide.
25. Protected Interface Modes in Symmetry-Enriched CFTs
Speaker: Saranesh Prembabu
Abstract:
Symmetry can enrich gapless phases so that two realizations of the same CFT become distinct once a global symmetry is specified, in analogy with gapped symmetry-protected topological (SPT) phases. I will argue that spatial interfaces provide a robust fingerprint of this enrichment: whenever two 1+1d CFTs represent different symmetry-enriched critical points, any symmetry-preserving interface between them must flow to a non-invertible conformal defect. These gapless interfaces are substantially more intricate than the familiar edge modes of gapped SPTs. When the enrichment is encoded in twisted-sector charges, the interface problem reduces to classifying conformal defects with anomalous symmetry action (a defect 't Hooft anomaly). I will illustrate these ideas in explicit Ising-chain realizations with $\mathbb{Z}_2 \times \mathbb{Z}_2^T$ symmetry, where we classify the conformal interfaces and find stable, spontaneous-symmetry-breaking degenerate modes, algebraically localized at the interface.
26. Entanglement structure of (1+1)-d boundary CFT
Speaker: Shuma Nakashiba
Abstract:
The entanglement structure of quantum systems has been extensively studied over the past two decades from both the high-energy perspective (motivated by black hole entropy) and the condensed-matter perspective (motivated by spin-chain systems). In (1+1)-dimensional QFT, entanglement entropy has been computed for both gapped and gapless systems. For the latter, one obtains the well-known scaling law, where the entanglement entropy grows logarithmically with subsystem size, with a coefficient proportional to the central charge. When a single boundary condition is imposed, the entanglement entropy acquires an additional constant contribution, the so-called boundary entropy.
However, the entanglement spectrum becomes much more nontrivial when different boundary conditions are imposed at the two ends. Although such systems can be treated numerically using straightforward DMRG, a general field-theoretical description is still lacking, except for a few integrable models.
In this poster, we study the entanglement entropy of systems with two (not necessarily identical) boundary conditions in a general CFT setup, and aim to clarify the relationship between symmetry and entanglement in boundary CFT.
27. Symmetry Spans and Enforced Gaplessness
Speaker: Takamasa Ando
Abstract:
Global symmetry is often useful in specifying IR dynamics of systems. For instance, some symmetries forbid unique gapped ground states via anomaly-matching arguments. However, ruling out any gapped ground states, including degenerate ones, is significantly harder. Although anomalies of continuous symmetries can exclude gapped theories, realizing these anomalous symmetries exactly on lattices with finite-dimensional on-site Hilbert spaces is presumably impossible.
In this work, we propose a different (but likely related) approach to exclude all gapped ground states. Specifically, we study situations where two different symmetries share a common symmetry—for example, where the two symmetries are non-invertible or continuous, and the common one is a non-anomalous group symmetry. We argue that such configurations, which we call symmetry spans, can forbid gapping. We clarify the argument for symmetry spans and gaplessness and illustrate it through concrete examples.
This presentation is based on ongoing work with Kantaro Ohmori (RIKEN iTHEMS).
28. The application of ZX-calculus in non-invertible symmetries
Speaker: Yanming Su
Abstract:
ZX-calculus is a powerful technique in quantum information which represents states and operators by graphs. We apply the technique to the study of non-invertible symmetries in quantum lattice models. ZX-calculus provides an efficient way to visualize a large amount of behaviors on lattice, such as the transformation laws of operators, movements of the topological defects and the fusion of both. We further combine ZX-calculus with the sandwich construction to generate new non-invertible symmetries and study their behaviors, which could be cumbersome in a purely algebraic approach.
29. Complex Conformal Field Theories in the Two-Dimensional Potts Model: Bulk and Boundary Perspectives
Speaker: Yin Tang
Abstract:
Complex conformal field theories (CFTs) have recently been invoked to describe weakly first-order phase transitions in statistical mechanics and walking renormalization-group behavior in gauge theories. Despite their broad conceptual relevance, concrete and controllable lattice realizations of complex CFTs remain scarce. Motivated by this challenge, we study complex CFTs in the two-dimensional (Q>4)-state Potts model, focusing on both bulk and boundary critical behavior. By introducing additional non-Hermitian interactions, we access complex fixed points in the complexified coupling space and use the state–operator correspondence to uncover their emergent Virasoro symmetry. Our results suggest that the pseudo-critical scaling in the original models is governed by nearby complex conformal fixed points. Furthermore, we demonstrate that complex conformality persists in the presence of boundaries, giving rise to nontrivial boundary criticality and complex boundary fixed points. Our results provide novel bulk and boundary perspectives on complex CFTs and clarify their role in pseudo-critical phenomena beyond the conventional unitary framework.
30. Extension, substructure and domain wall: Fusion ring-based classification of CFTs and TQFTs
Speaker: Yoshiki Fukusumi
Abstract:
The renormalization group, combined with symmetry analysis, is one of the most powerful frameworks in theoretical physics. Recently, the notions of symmetry have been extended from a group to a ring. Hence, the classification of rings is the most fundamental in studying the corresponding RGs, but this research direction has been under development.
In this presentation, I will summarize our recent findings studying such classifications based on the established mathematical frameworks, linear algebra, and ring theory. Our discussion provides a rigorous classification of symmetries applicable to the quantum Hamiltonian in quantum field theories and the corresponding lattice models. In particular, I present several algebraic data of new series of renormalization group domain walls (gapped domain walls) in CFTs (in TQFTs). There exist references investigating the formal structure of such objects. However, the exact coefficients and related quantities have rarely been obtained in an accessible way, and one can resolve part of the difficulties with our method.
This presentation is based on ongoing projects with Taishi Kawamoto, arXiv:2508.08639 with Shinichiro Yahagi, and arXiv:2506.23155 with Yuma Furuta.
31. Exotic theta terms in 2+1d fractonic field theory
Speaker: Yuki Furukawa
Abstract:
In this work, we study exotic theta terms in 2+1d $\phi$-theory, which is a continuum description of the XY-plaquette model. The $\phi$-theory is a fractonic analogue of the 1+1d compact boson and has momentum and winding subsystem symmetries. We study two types of theta angles, which we call a bulk and a foliated theta angle. The foliated theta term can be constructed by coupling winding currents on neighboring leaves of a foliation. Notably, one can allow the foliated theta angle to vary spatially without affecting the local dynamics. Both theta angles lead to generalized Witten effects where vortex operators carrying winding subsystem charge acquire momentum subsystem charge. In the case of the foliated theta angle, the Witten effect is more subtle; a vortex operator carries a quadrupolar momentum charge. We demonstrate these features with lattice realizations based on the modified Villain formalism.
