09:00 to 09:45 
Raghu Mahajan (Stanford University, USA) 
Giant graviton expansion from eigenvalue instantons Recently, S. Murthy has proposed a convergent expansion of free partition functions and superconformal indices of finiteN purely adjoint gauge theories based on a Fredholm determinant expansion. This expansion has been dubbed the giant graviton expansion and takes the form of an infinite series of corrections to the N=∞ result, with the mth correction being of order exp(−mN). We show that this expansion can be reproduced using eigenvalue instantons in unitary matrix integrals. This perspective allows us to get the giant graviton expansion without the intermediate step of the Hubbard Stratonovich transformation.



09:45 to 10:30 
Shiraz Minwalla (TIFR Mumbai, India) 
Level Rank Duality in Quantum Mechanics We formulate the non relativistic quantum description of a collection of particles, in specified but arbitrary representations of the gauge group, interacting via a Chern Simons coupled gauge field. We argue that the quantum systems so constructed enjoy invariance under level rank duality.



11:00 to 11:45 
Michael Heller (Ghent University, Belgium) 
Geometric interpretation of holographic timelike entanglement entropy Analytic continuations of areas of RyuTakayanagi surfaces in which the boundary subregion becomes extended along a timelike direction brought a promise of a novel, timecentric probe of the emergence of spacetime. We propose that the bulk carrier of this holographic timelike entanglement entropy are boundaryanchored extremal surfaces probing analytic continuation of holographic spacetimes into complex coordinates. This not only provides a geometric interpretation of all the known cases obtained by direct analytic continuation of closed form expressions of holographic entanglement entropy of a strip subregion, but crucially also opens a window to study holographic timelike entanglement entropy in full generality. To better understand what the prescription for holographic timelike entanglement entropy entails we study complex extremal surfaces anchored on a timelike strip on the boundary of antide Sitter black hole spacetimes. Our investigation reveals the existence of multiple complex extremal surfaces in these cases. We discuss physical principles that can be utilized to single out the physical contribution.



11:45 to 12:30 
Mukund Rangamani (UC Davis, USA) 
Looking at extremal black holes from very far away We have now come to understand that extremal black holes are like ordinary quantum systems with a few degrees of freedom, and no macroscopic degeneracy. The classical black hole entropy receives quantum corrections, from collective modes localized in the nearhorizon region, that lowers the density of states. I will describe an alternate perspective on these quantum effects, focusing on the entire spacetime. Specifically, I will argue that the nearextremal black holes support a set of lowlying gapless modes which are responsible for this suppression of the degeneracy at low temperatures.



14:00 to 14:45 
Justin David (IISc, India) 
Precision tests of bulk entanglement entropy We consider linear superpositions of single particle excitations in a scalar field theory on AdS3 and evaluate their contribution to the bulk entanglement entropy across the RyuTakayanagi surface. We compare the entanglement entropy of these excitations obtained using the FaulknerLewkowyczMaldacena formula to the entanglement entropy of linear superposition of global descendants of a conformal primary in a large c CFT obtained using the replica trick. We show that the closed from expressions for the entanglement entropy in the small interval expansion both in gravity and the CFT precisely agree. The agreement serves as a nontrivial check of the FLM formula for the quantum corrections to holographic entropy which also involves a contribution from the back reacted minimal area. Our checks includes an example in which the state is time dependent and spatially inhomogenous as well another example involving a coherent state with a Bañados geometry as its holographic dual.



14:45 to 15:30 
Norihiro Iizuka ( National Tsing Hua University, Taiwan & YITP, Kyoto, Japan) 
Krylov complexity as an order parameter for deconfinement phase transitions at large N 


16:00 to 16:45 
K. Narayan (Chennai Mathematical Institute, India) 
de Sitter space, extremal surfaces and time entanglement I will describe extremal surfaces in de Sitter space anchored at the future boundary I+. Since such surfaces do not return, they require extra data in the past. In entirely Lorentzian dS, this leads to futurepast timelike surfaces stretching between I+/I, with pure imaginary area (relative to spacelike surfaces in AdS). With a noboundary type boundary condition, the top half of these joins with a spacelike part on the hemisphere giving a complexvalued area. These can be thought of as certain analytic continuations from AdS while also amounting to spacetime rotations. The areas are best interpreted as pseudoentropy or timeentanglement (entanglementlike structures with timelike separations). I will also briefly discuss multiple subregions, entropy relations, the pseudoentanglement wedge, a heuristic LewkowyczMaldacena formulation, as well as aspects in toy models in quantum mechanics, involving the time evolution operator, reduced transition amplitudes, and futurepast entangled states.



16:45 to 18:00 
 
Short talks 

