Highly excited string scattering(HESS) can be thought of as dual to black hole (BH) scattering, as conjectured by Susskind, Horowitz, and Polchinski. In recent times, Rosenhaus and Gross have pointed out that there is a notion of chaos/randomness in these fully quantum scattering amplitudes, which can be explained from the perspective of a multiparticle scattering process with a number of particles being very high. Due to the HESS-BH duality, this acts as a stronger-than-semiclassical indicator of chaos in black holes. I will discuss how this idea, initially discussed qualitatively, can be made quantitative by studying the position of the peaks and treating them as eigenvalues of a fictitious Hamiltonian. I will discuss various probes such as level statistics, scattering form factors, and the spread complexity of the fictitious Hamiltonian evolution as quantitative indicators of chaos by comparing them with random matrix universality classes.
Strings: Monday, 07/04/2025, 14:00, Room 226
Diego Trancanelli (University of Modena, Modena)
Conformal defects and RG flows in ABJM
Defects play a central role in many contexts, from condensed matter to quantum gravity. The situations in which the bulk theory is conformal and the defect inherits part of this symmetry -- the so-called defect conformal field theories (dCFTs) -- have recently received a lot of attention, also thanks to new powerful methods to tackle them, like supersymmetric localization, integrability or the bootstrap. A dCFT may be deformed by turning on marginally relevant operators, which trigger RG flows connecting different fixed points. A natural arena where this phenomenon can be explored are 3-dimensional Chern-Simons theories coupled to matter. These are in fact known to display a plethora of Wilson loops that can be used to define 1-dimensional dCFTs living on their contours. In this talk we discuss a few examples from an intricate web of RG flows connecting the dCFTs defined on the BPS and non-BPS Wilson loops of ABJM theory. We compute the anomalous dimensions of the deforming operators, establish g-theorems along the flows, and also discuss the role played by cohomological anomalies and framing. Based on: 2211.16501, 2305.01647, 2312.13283, 2410.10970.
Strings: Monday, TBA, 14:00, Room 226
Saebyeok Jeong (CERN, Geneva)
Miura operators as R-matrices from M-brane Intersections
I will discuss how M2-M5 intersections in the twisted M-theory background yield R-matrices of quantum toroidal algebra of gl(1). These intersections are also identified as Miura operators, providing the Miura transformation for the q-deformed W- and Y-algebras. Consequently, the intertwining relation of the q-deformed Maulik-Okounkov R-matrix is illuminated as a Yang-Baxter equation, in particular. Also, I will explain the M2-M5 intersection (equivalently the Miura operator) gives rise to the qq-characters of the 5d N=1 gauge theory, illuminating an algebraic meaning of the latter.
Strings: Monday, 05/05/2025, 14:00, Room 226
Giuseppe Policastro (Ecole Normale Supérieure, Paris)
TBA
TBA
Strings: Monday, 26/05/2025, 14:00, Room 226
Seyed Morteza Hosseini (Queen Mary University of London, London)
TBA
TBA