Welcome

Talk 1 - Joel Karlsson 

Title: Quantum Liouville Cosmology

Abstract: There is a need for quantum cosmology models under complete theoretical control to put the framework on solid ground. Timelike Liouville theory provides a tractable example of such a model that admits a semiclassical limit dominated by a real sphere saddle. In this talk, I will report on a detailed analysis of the disk path integral of this theory, which gives rise to states akin to the Hartle-Hawking wavefunction. Working at fixed trace of the extrinsic curvature, K, a suitable pairing of Liouville disk path integrals yields a K-independent quantity that may serve as the basis for a well-defined inner product. I will also comment on the fixed-area ensemble, which features hyperbolic saddles as well, the phase of the path integral and a natural generalization to higher dimensions. 

Coffee

Talk 2 - Alan Rios Fukelman

Title: de Sitter pUniverses 

Abstract: In this talk I will discuss recent developments in de Sitter QFTs through the study of certain solvable theories. I will analyse a simple extension of the Schwinger model where the charged massless fermions carry non-unit integer charge $p$. The model has discrete zero- and one-form global symmetries that are spontaneously broking, yielding $p$ degenerate ground states, which are de Sitter invariant and satisfy the Hadamard property. Finally, I will discuss how this model can be coupled to a theory of quantum gravity that admits a semiclassical de Sitter saddle.  

Lunch

Talk 3 - Oscar Dias

Title: Localised thermal phases in BFSS quantum mechanics

Abstract: We investigate the low-energy regime of BFSS quantum mechanics using its holographic dual. We identify three distinct thermodynamic phases (black holes) and analyze their thermodynamic properties extensively, including phase transitions amongst the several phases. While the properties of the canonical ensemble aligns with existing conjectures on BFSS thermodynamics, we uncover intriguing and unexpected behavior in the microcanonical ensemble. Specifically, for sufficiently low energies, we observe the dominance of the localized phase. Surprisingly, we also identify an energy range where the non-uniform phase becomes dominant.

Coffee

Talk 4 - Hynek Paul

Title: Correlation functions for non-conformal Dp-brane holography

Abstract:  I will explain how we can study correlation functions of local operators in d-dimensional maximally supersymmetric Yang-Mills theories in the planar strongly-coupled limit via holography. The relevant supergravity backgrounds (obtained from the near-horizon limit of Dp-branes with p=d-1) enjoy a scaling similarity, giving rise to an auxiliary AdS space. This allows us to derive simple rules analogous to Witten diagrams for the holographic calculation of correlation functions in this non-conformal setup. Using this framework, I will then explain how to analytically compute two- and three-point correlators of scalar operators, leading to new results which could be tested using lattice QFT methods. Based on [2503.18770] with Nikolay Bobev and Guillermo Mera Álvarez, and work in progress. 

Talk 5 - Shota Komatsu

Title: No Shift, Sherlock 

Abstract:  

Talk 5 - Ziqi Yan 

Title: Revisiting Decoupling Limits for Holography 

Abstract: I will revisit the decoupling limits leading to matrix theories on D-branes and their associated holographic constructions in string theory, focusing on non-Lorentzian geometric aspects. I will discuss the dynamics of the associated non-Lorentzian supergravity and its string-theoretic origin. Finally, I will discuss implications of these unconventional non-Lorentzian features for holography.  

Coffee

Talk 6 - Celine Zwikel

Title: New symmetries at spatial infinity

Abstract: I will investigate the asymptotic symmetries of four-dimensional asymptotically flat spacetimes at spatial infinity using covariant phase space methods. I will show that novel symmetries can be realized—beyond those identified at null infinity—namely logarithmic translations and log-supertranslations. The associated charges are finite and conserved, and we show that their algebra admits non-trivial central extensions. I will conclude with interesting avenues that this work opens.

Lunch

Talk 7 - Marija Tomasevic

Title: How traversable is a traversable wormhole?

Abstract: To answer the above question, we study low-frequency scattering in the four-dimensional traversable wormhole of Maldacena, Milekhin, and Popov. The resulting transmission probabilities reveal that wormhole traversability depends strongly on the nature of the probe. For scalar probes, both neutral and charged, traversability depends on the time scale. On time scales of order the light-crossing time after sending in a signal, the transmission is parametrically suppressed, with most of the incoming signal reflected or temporarily trapped inside the wormhole throat. As time progresses, the trapped signal gradually leaks out, so that at late times the accumulated transmission cross-section approaches one half of the corresponding black hole absorption cross-section. Despite this generic suppression at low frequencies, the transmission spectrum also exhibits resonant frequencies at which transmission becomes perfect. Charged massless fermions tell a very different story. Unlike scalars, they traverse the wormhole with essentially unit probability at low energies. The same mechanism underlies their efficient absorption by magnetic black holes and realizes a channel closely analogous to the Callan-Rubakov effect, revealing unexpected connections with monopole-fermion scattering. Putting everything together, we conclude that scalar probes are best suited for uncovering distinct features of these magnetic wormholes, while charged massless fermions are the ideal carriers of information through them.

Coffee

Talk 8 - Kiarash Naderi

Title: 2d Yang-Mills and AdS3/CFT2 

Abstract: Motivated by tensionless strings on AdS3, we investigate a world-sheet description of pure 2d Yang-Mills (YM) on a Riemann surface. More specifically, we study the relation between partition functions and correlators of pure 2d YM and symmetric orbifold theories. We present a topological string description of 2d YM and a few computations as a check. Based on an on-going work with Matthias Gaberdiel and Bob Knighton.