String Theory Seminar: Claire Zukowski (UMN) “Wilson Spools and de Sitter Quantum Gravity”
I will propose a mechanism, based on the Chern-Simons formulation of three-dimensional Euclidean gravity, that couples matter fields to three-dimensional de Sitter quantum gravity. First, I will derive su(2) representations that differ in Hermiticity choice from the usual unitary representations; these are important for gravitational applications of Chern-Simons theory. I will then introduce the concept of a “Wilson spool” constructed … Read More
String Theory: Leonard Susskind (Stanford) “DSSYK, de Sitter holography, and the ‘t Hooft Meson model”
Abstract:The proposal that DSSYK at infinite temperature is dual to JT deSitter space leads to the question of what the bulk theory is like, its particle spectrum, forces, fields etc. I will answer that question by examining the emergent symmetries of the double scaled limit. The answer: The ‘t Hooft model 2D QCD. The spectrum consists of a Regge-like trajectory … Read More
Stefano Antonini (UC Berkeley) “Living on the edge: part I”
Abstract: In this talk I will discuss an entropic puzzle in pure JT gravity and its resolution, which requires taking into account (doubly) non-perturbative effects in the gravitational path integral. In JT gravity, which is dual to a random matrix ensemble, the gravitational thermal entropy becomes negative at very low temperatures. This puzzle arises when computing the annealed (instead of quenched) entropy, … Read More
Patrick Tran (UC Berkeley) “Living on the edge: part II”
Abstract: In this talk, I will discuss an information paradox in black hole physics where the entanglement entropy across a two-sided black hole can become negative when inserting a large number of matter excitations behind the black hole horizon. First posed by Lin, Maldacena, Rosenberg, and Shan in two-sided BPS black holes in SUSY JT gravity, I will show this paradox … Read More
Misha Usatyuk “Revisiting ADE minimal string theories”
Abstract: Minimal string theories provide some of the simplest examples of holographic dualities, where low-dimensional theories of quantum gravity are dual to matrix integrals. The most studied example is the worldsheet theory defined by the A-series minimal model coupled to Liouville CFT, which is dual to a solvable two-matrix integral. In this talk I will give an overview of low … Read More
String Special Seminar: Dan Stefan Eniceicu (Stanford) “The complete non-perturbative partition function of $\mathcal{N}=1$ minimal superstring theory and JT supergravity”
Abstract: We derive a convergent analytic expression for the partition function of the $\mathcal{N}=1$ $(2,4k)$ minimal superstring theory with type 0B GSO projection in the ungapped phase by leveraging the duality between this theory and a double-scaled unitary matrix integral. Taking the $k\rightarrow\infty$ limit, we also obtain the complete partition function of $\mathcal{N}=1$ JT supergravity, including all contributions associated with … Read More
Douglas Stanford (Stanford) “Cusps as counterterms in 3d gravity”
Three dimensional hyperbolic manifolds have accumulation points in the spectrum of their volumes, leading to a divergence in the sum over topologies. The limit points are cusped hyperbolic manifolds, and we propose to renormalize the sum by including the cusped manifold as a counterterm. This gives a reinterpretation of the zeta-function regularization procedure used by Maloney and Witten in the … Read More
Jeevan Chandra (UC Berkeley) “Statistics in 3d gravity from knots and links”
Abstract: In recent years, there has been remarkable progress in evaluating wormhole amplitudes in 3d Einstein gravity with negative cosmological constant and matching them to statistics of 2d CFT data. In the talk, I will first give an overview of how wormholes in 3d gravity capture the universal matrix element statistics of local operators in 2d CFT and of certain … Read More
Jiuci Xu (USB) “Quantum Symmetry and Geometry from Chords”
Abstract: The emergence of the quantum R-matrix in the double-scaled SYK model suggests a hidden quantum group structure. In this talk, I will demonstrate how the quantum group U_q(su(1,1)) underlies the structure of the chord Hilbert space with matter insertions. Specifically, we construct an isometric factorization of one-particle states into two boundary states without matter, allowing a decomposition of the one-particle … Read More
Emil Aleksander Albrychiewicz (UCB) “Analytic Torsion from Chern-Simons theory via the (2,0)-theory on Dicyclic Orbifolds of 3-sphere.”
The Witten index of the (2, 0)-theory compactified on spaces of the form S^3/ΓxS^2 , with a freely acting group Γ, and with external string sources implemented via timelike surface operator insertions, is expressed in terms of Ray-Singer torsion of S ^3/Γ and characters of irreducible representations of Γ. We compute it explicitly for the Dicyclic groups. The torsion and … Read More