Events Archive

IAS HET Seminar |David Berenstein, University of California, Santa Barbara “Staggered Bosons, Kahler Dirac Bosons and Supersymmetry on the Lattice” | Bloomberg Lecture Hall (IAS) & Zoom
Mon, Apr 15, 2024, 2:30 pm3:30 pm

I will describe constructions of lattice field theories that assign a single bosonic variable to each site, rather a conjugate pair x,p. The information to realize a non-trivial dynamics is realized by non-trivial Poisson brackets between nearest neighbors. The construction is similar to staggered fermions in 1+1…

HET Seminar |Nikolay Bobev, Ku Leuven | “A Holographic Trilogy at Large N: The Power, the Logarithm, and the Exponent” |PCTS
Fri, Apr 12, 2024, 2:00 pm3:00 pm

I will summarize recent results on the large N limit of path integrals of 3d SCFTs arising on the worldvolume of N M2-branes placed on compact Euclidean manifolds. The leading N^3/2 term in the large N expansion of these "free energies" receives 1/N, log(N), as well as exponentially suppressed corrections that can be…

IAS HET Seminar | Nathan Haouzi, Member, School of Natural Sciences, IAS| “The Miura Operator is an R-matrix, via Intersecting Branes” | Bloomberg Lecture Hall (IAS) & Zoom
Fri, Apr 12, 2024, 11:00 am12:00 pm

 The Miura transformation is a powerful formalism to construct generators of vertex operator algebras in free field representation. In this talk, I will explain that Miura operators are R-matrices of a certain quantum algebra, and comment on physical implications. I will also describe how to…

HET Seminar |Victor Rodriguez, Princeton University| “New Dualities Between String Theories and Random Ensembles” | PCTS
Tue, Apr 9, 2024, 2:00 pm3:00 pm

I will introduce two new families of critical string theories in two dimensions and explain that, when viewed as two-dimensional quantum gravity on the worldsheet, each is equivalent to a matrix model. The first worldsheet string theory consists of Liouville CFT coupled to timelike Liouville CFT. Its dual double-scaled…

HET Seminar |Aki Hashimoto, University of Wisconsin-Madison| “Aspects of T Tbar deformation and the kernel formula” | PCTS
Mon, Apr 1, 2024, 2:30 pm3:30 pm

In this talk, I will review a simple derivation of an integral kernel formula for the partition function of T Tbar deformed CFT based on the holographic single trace T Tbar deformation and its generalization to J Tbar and J Jbar deformations. I will then describe the application of this formalism to…

IAS HET Seminar | Chris Akers, Member, School of Natural Sciences, IAS, | “Multipartite Edge Modes and Tensor Networks” | Wolfensohn Hall (IAS) & Zoom
Fri, Mar 29, 2024, 11:00 am12:00 pm

Holographic tensor networks model AdS/CFT, but so far they have been limited by involving only systems that are very different from gravity. Unfortunately, we cannot straightforwardly discretize gravity to incorporate it, because that would break diffeomorphism invariance. In this talk I will present a resolution,…

IAS HET Seminar | Mukund Rangamani, University of California, Davis, | “Superstring Partition Functions in AdS3” | Bloomberg Lecture Hall (IAS) & Zoom
Mon, Mar 11, 2024, 2:30 pm3:30 pm

I will describe the one-loop partition function for strings propagating on AdS3 geometries with NS-NS flux (for generic values of AdS radius in string units). The essential ingredients that go into this analysis have been known for a while. The goal will be to organize the result to facilitate comparison to…

HET Seminar |Minjae Cho, Princeton| “A (non-)worldsheet description of strings in AdS and flux compactifications” | PCTS
Mon, Mar 4, 2024, 2:30 pm3:30 pm

 For backgrounds with known exact worldsheet theory descriptions, ordinary string perturbation theory can be employed to study observables such as spectrum and scattering. However, the majority of interesting string backgrounds, including AdS and flux compactifications, lack such descriptions, posing challenges in…

IAS HET Seminar | Daniel Jafferis, Visiting Professor, Institute for Advanced Study; Harvard University| “Tensor Model for 3d Gravity” | Bloomberg Lecture Hall & Zoom
Fri, Mar 1, 2024, 11:00 am12:00 pm

I will describe a double scaled matrix and tensor integral whose Feynman diagrams can be organized in a 3d topological expansion which agrees term by term with partition functions of 3d gravity. The integral is taken over CFT2 data, and the limiting potential imposes bootstrap constraints. The conjecture that the…

IAS HET Seminar | Aron Wall, Member, School of Natural Sciences, IAS; University of Cambridge| “What is the Symmetry Class of Bulk Holography?” | Bloomberg Lecture Hall & Zoom
Fri, Feb 16, 2024, 11:00 am12:00 pm

The TTbar deformation is a holographic theory describing holography a finite distance in the bulk.   If this theory can be UV completed, it could be a model of nonperturbative bulk quantum gravity.  However, it seems to be a non-unitary theory, as the energy eigenvalues lie either on the real axis or the…

IAS HET Seminar | Zohar Komargodski, SCGP, Stony Brook University | “Semi-Classical Physics at Large Quantum Numbers” | Bloomberg Lecture Hall (IAS) & Zoom
Mon, Feb 12, 2024, 2:30 pm3:30 pm

We will discuss excitations with large spin and/or large particle number. For conformal theories this corresponds to investigating particular trajectories of heavy operators.

We find trajectories with large approximate degeneracy and show that they can be understood as coherent rotating fluids with…

HET Seminar |Ross Dempsey, Princeton| “Phase Diagram of the Two-Flavor Schwinger Model at Zero Temperature” | PCTS
Fri, Feb 9, 2024, 11:00 am12:00 pm

The Schwinger model of two-dimensional quantum electrodynamics is among the oldest and best-studied quantum field theories, and is attracting renewed interest in connection with simulations of quantum lattice Hamiltonians. I will discuss an improved lattice formulation of the model, and show how it drastically…

IAS HET Seminar | Greg Moore, Distinguished Visiting Professor, School of Natural Sciences, IAS; Rutgers University | “Update on Supersymmetric Field Theory and Invariants of Smooth Four-Manifolds” | Bloomberg Lecture Hall (IAS) & Zoom
Fri, Feb 2, 2024, 11:00 am12:00 pm

I will give a lightning review of results on this subject from 1988-1998 and then describe more recent developments, mostly current work in progress.  First, I will describe topological twisting of Lagrangian N=2 d=4 field theories in terms of the general concept of reduction of structure group. Second, I will…

IAS HET Seminar | Yin-Chen He, Perimeter Institute, | “Fuzzy Sphere Regularization of 3D CFTs” | Bloomberg Lecture Hall (IAS) & Zoom
Mon, Jan 29, 2024, 2:30 pm3:30 pm

Conformal Field Theory (CFT) represents a class of quantum field theories that has profound applications across various physics domains, from critical phenomena in statistical mechanics to quantum matter, quantum gravity, and string theory. In this talk, I will introduce our recently proposed 'fuzzy (non-commutative)…

HET Seminar |Junho Hong, KU Leuven| “Log Corrections in AdS4/CFT3 ” | Jadwin A09
Fri, Jan 12, 2024, 11:00 am12:00 pm

I will discuss log corrections to the gravitational path integral around asymptotically Euclidean AdS4 backgrounds that arise from the compactification of string/M-theory. The heat kernel method will be utilized, which divides the log correction into local and non-local contributions. The local contribution is…

IAS HET Seminar | Erez Urbach, Weizmann Institute of Science | “The Black Hole/String Transition in anti de Sitter Space” | Bloomberg Lecture Hall (IAS) & Zoom
Mon, Dec 4, 2023, 2:30 pm3:30 pm

String stars, or Horowitz-Polchinski solutions, are string theory saddles with normalizable condensates of thermal-winding strings. In the past, string stars were offered as a possible description of stringy (Euclidean) black holes in asymptotically flat spacetime, close to the Hagedorn temperature. I will discuss the…

HET Seminar |Jnan Maharana; Institute of Physics, Bhubaneswa | “ IS THE SCATTERING AMPLITUDE ANALYTIC IN A FIELD THEORY WITH A COMPACT SPATIAL COORDINATE?” | PCTS
Fri, Nov 17, 2023, 11:00 am12:00 pm

Khuri, in 1995, considered potential scattering for a model where one spatial coordinate in compactified on the circle. He adopted Greens function method to study analyticity property of scattering amplitude. His conclusion was that forward scattering amplitude does not satisfy dispersion relations in certain cases;…

HET Seminar | Arkady Tseytlin,Imperial College London | “Quantum M2 branes and AdS/CFT” | Joseph Henry Room
Mon, Nov 6, 2023, 2:30 pm3:30 pm

We will review some recent work with M. Beccaria and S. Giombi
 on  checking AdS/CFT duality by reproducing certain   supersymmetric  localization results
 in 3d  superconformal  Chern-Simons-matter (ABJM) theory  by semiclassical
 quantization of &nbsp…

HET Seminar |Christian Jepsen, Stonybrook| “Challenges to q-deformed String Theory Amplitudes” | Jadwin A06
Fri, Oct 27, 2023, 2:00 pm3:00 pm

Progress in recent years on the S-matrix bootstrap and bottom-up constructions of candidate string theory amplitudes, have brought about a revival of interest in the so-called Coon amplitude: a q-deformed generalization of the Veneziano amplitude exhibiting a semi-infinite sequence of poles that converge on an accumulation point, from which a…

IAS HET Seminar | Nikita Sopenko, Member, School of Natural Sciences, IAS| “Equivariant Higher Berry Classes for Quantum Many-Body Systems” | Bloomberg Lecture Hall (IAS) & Zoom
Fri, Oct 20, 2023, 11:00 am11:00 am

I will talk about the invariants of topologically ordered states of quantum lattice systems that generalize Berry classes and can be defined for any gapped state in any dimension. The equivariant version of such invariants unifies and generalizes the Hall conductance and the Thouless pump. I will also discuss the…