Journal clubs are on Tuesdays from 13 to 14 in Seminar Room 3 (building 1).
Feel free to suggest papers in the comments section. Note that you can also add attachments and comment on other people's suggestions.
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Spring/Summer semester 2019
Journal club 10-12-2019
- Fabrizio del Monte (SISSA), TBA.
Journal club 03-12-2019
Jack Foster (Southampton University), TBA.
Journal club 26-11-2019
- Francesco Galvano (Torino): Wilson loops in N=2 SuperConformal Field theories (This seminar will take place in Building 3 Seminar room BAH 2)
Abstract: The partition function of a four dimensional N=2 Super Yang-Mills theory can be mapped to a matrix model on a sphere using supersymmetric localization. We write it in a superconformal case, playing with the matter content in different representations of the gauge group. In this set-up we compute the vacuum expectation value a 1/2 BPS Maldacena-Wilson loop and we mention possible holographic consequences of this achievement. Finally, we discuss how the localization approach in presence of Wilson loops can capture other interesting observables, such as chiral correlators and the stress tensor one point function, up to a geometry deformation.
Journal club 19-11-2019
- No seminar scheduled.
Journal club 12-11-2019
- Zhengwen Liu: Scattering Equations and Multi-Regge Kinematics
Abstract: The scattering equations, a system of algebraic equations connecting the space of kinematic invariants and the moduli space of punctured Riemann spheres, provide a novel way to construct scattering amplitudes. In this framework, the tree-level S-matrix in many quantum field theories can be reformulated as a multiple integral that is entirely localized on the zeroes of the scattering equations. After presenting a very minimal introduction to the scattering equations, I will discuss the asymptotic behavior of the scattering equations in the so-called Multi-Regge kinematic regime and the corresponding factorizations of amplitudes in gauge theory and gravity.
Multi-Regge kinematics and the scattering equations
Gravitational Scattering in the High-Energy Limit
Journal club 05-11-2019
- Yuta Sekiguchi (U. Bern, AEC), O(d,d) transformations preserve classical integrability.
Abstract: We studied the classical integrability of O(d,d) transformations including not only O(d,d;Z) duality but also global O(d,d;R) deformation. The latter is known in the traditional literature to generate so-called current-current (JJbar) deformations of 2D CFTs. In this talk, I first plan to give brief reviews Yang-Baxter deformations of string backgrounds as well as the doubled sigma model. Then I will present how to construct the Lax pairs in the O(d,d) deformed WZNW models via O(d,d) map through very easy examples. The resulting Lax connections are in general non-local because they depend on the winding modes. Finally I will briefly comment on open questions under consideration in relation to the recent irrelevant integrable deformation. This talk is based on the recent work [1907.03759] with Domenico Orlando, Susanne Reffert and Kentaroh Yoshida.
Journal club 29-10-2019
Till Bargheer: Exact Four-Point Functions: Genus Expansion and Strong Coupling (This seminar will take place in Building 3 Seminar room BAH 2)
Using integrability, correlation functions of local operators in planar N=4 super Yang-Mills theory can be computed by reconstructing the dual worldsheet from a set of "hexagon" patches via "gluing" (performing complete state sums over mirror Bethe states). After reviewing this general procedure, I will explain how it can be used to compute a certain class of four-point correlators as an exact function of the coupling at any order in the 1/Nc genus expansion, and how the resulting series can be re-summed (via a suitable matrix model) to recover the full Nc dependence. If time permits, I will also comment on the strong-coupling limit of these correlators.
Journal club 22-10-2019
Gleb Kotousov: "Reflection operators in integrable QFT".
Journal club 15-10-2019
Sylvain Lacroix, Gauge Theory And Integrability, III (focusing on the second part about "disorder defects").
Journal club 08-10-2019
Alessandro Pini, Extremal Correlators and Random Matrix Theory.
Journal club 17-09-2019
Journal club 10-09-2019
- Philipp Tontsch, The Conformal Bootstrap at Finite Temperature
Journal club 06-08-2019
Journal club 02-07-2019
Journal club 25-06-2019
- Nikolay Bobev, How to Embrace a Naked Singularity
Journal club 18-06-2019
- Mikhail Isachenkov, Solving large N double-scaled SYK
Abstract: I will review a method to evaluate correlation functions of certain statistical systems via chord diagrams and apply it to compute correlators in the double-scaled version of SYK model, in particular in its large N limit. The results are exact at all energies and allow to extract corrections to the maximal Lyapunov exponent. Time permitting, I will comment on the suggested relation of this model to a Hamiltonian reduction of quantum particle moving on the non-compact quantum group SU_q(1,1).
Journal club 11-06-2019
- Alessandro Pini, Black holes in 4d N=4 Super-Yang-Mills
Journal club 04-06-2019 (cancelled)
Journal club 28-05-2019
- Lorenzo Quintavalle, Scattering Amplitudes For All Masses and Spins
- Georgios Papathanasiou, Energy-energy correlations at next-to-next-to-leading order.
- Extra references: ...
Journal club 21-05-2019
- Ilija Buric, Superconformal Blocks: General Theory
Journal club 14-05-2019
- Pedro Liendo, Sphere Packing and Quantum Gravity part 1
- Volker Schomerus, Sphere Packing and Quantum Gravity part 2
- Fabrizio Nieri, Overview on localization