“Strings, CFT & Integrability” – Spring Semester 2018

Wed

31.01.

11:30

HIT E41.1

Pujian Mao (Chinese Academy of Sciences, Beijing)

“The triangle relation and beyond”

abstract (click to view) Soft theorems, memory effects, and asymptotic symmetries have been shown in recent years to be mathematically equivalent. In this talk, I will give an overview of this fascinating triangle equivalence. In particular, I will explain in detail a very recent prescription to realize this triangle relation beyond the leading order. (click to hide)

Tue

20.02.

14:00

HIT E41.1

Shota Komatsu (IAS Princeton)

“Exact Correlators on the BPS Wilson Loops”

Tue

27.02.

14:00

HIT E41.1

Nicolas Boulanger (University of Mons)

“Uniqueness of N=2 and 3 pure supergravities in 4D”

Wed

28.02.

09:30

HIT E41.1

Arkady Tseytlin (Imperial College, London)

“Non-supersymmetric Wilson loop in N=4 SYM and 1d CFT”

Tue

06.03.

14:00

HIT E41.1

Max Riegler (ULB)

“Warped Black Holes in Lower Spin Gravity”

abstract (click to view) In this talk I present a novel and very efficient description of space-like warped Anti-de Sitter black holes in terms of a lower-spin Chern-Simons theory. I will explain in detail how to treat the thermodynamics of these black holes in the Chern-Simons formulation and what initial assumptions have to be made. In the rest of the talk I will take great care to explain why these initial assumptions are reasonable using various arguments such as: arguments based on warped conformal field theories, holographic entanglement entropy and a metric interpretation of the Chern-Simons results. I will also mention how these results can be used for possible higher-spin extensions of space-like warped higher-spin black holes. (click to hide)

Tue

13.03.

14:00

HIT E41.1

Julian Sonner (University of Geneva)

“Black Holes as Pure States”

Tue

20.03.

14:00

HIT E41.1

Kirill Krasnov (University of Nottingham)

“Colour/kinematics duality in YM and the Drinfeld double of the Lie algebra of diffeomorphisms”

Tue

27.03.

14:00

HIT E41.1

Konstantin Zarembo (Nordita)

“String quantum corrections to holographic Wilson loops”

abstract (click to view) Minimal area law, that holds for Wilson loops at strictly infinite coupling, has been extensively checked using localization and integrability. Computing quantum corrections to the area law at the same time is riddled with puzzles. I will concentrate on the ratio of Wilson loops that share the same contour on the boundary but have different coupling to scalars. A mismatch between field theory and holography has been reported for a ratio of this type. I will show that an IR anomaly associated with the singular conformal gauge has to be taken into account to reconcile the string calculation with the known field theory result for the Wilson loops. (click to hide)

Wed

28.03.

14:00

HIT E41.1

Till Bargheer (Uni Hannover)

“Handling Handles -- Non-Planar AdS/CFT Integrability”

abstract (click to view) I will explain how non-planar corrections to correlation functions in
N=4 super Yang-Mills theory can be computed via the recently developed
integrability-based method of hexagonalization.
Reference: https://arxiv.org/abs/1711.05326 (click to hide)

Tue

24.04.

14:00

HIT E41.1

Amit Sever (Tel Aviv University)

“Non-planar Scattering amplitudes in N=4 SYM theory”

abstract (click to view) I'll discuss the paper 1802.09395 where we study the first non-planar correction to gluon scattering amplitudes in N=4 SYM theory. The correction takes the form of a double trace partial amplitude and is suppressed by one power of 1/N with respect to the leading single trace contribution. We extend the duality between planar scattering amplitudes and null polygonal Wilson loops to the double trace amplitude. The new duality relates the amplitude to the correlation function of two infinite null polygonal Wilson lines that are subject to a quantum periodicity constraint. We test the duality perturbatively at one-loop order and demonstrate it for the dual string in AdS. The duality allows us to extend the notion of the loop integrand beyond the planar limit and to determine it using recursion relations. It also allows us to apply the integrability-based pentagon operator product expansion approach to the first non-planar order. (click to hide)

Tue

08.05.

14:00

HIT E41.1

Sara Pasquetti (Milano Bicocca)

“T[SU(N)] duality webs”

abstract (click to view) I will discuss various new IR dualities between 3d N=2 quiver theories. Some of the 3d theories that I will discuss can be interpreted as codimension-two defect theories coupled to a 5d bulk theory, in this case the 3d duality follows from a duality for the bulk theory. Finally I will discuss the gauge/q-CFT correspondence relating pairs of 3d dual theories to spectral dual correlators of q-deformed Toda vertex operators and discuss the reduction from 3d to 2d. (click to hide)

Wed

16.05.

11:00

HIT E41.1

Roberto Volpato (INFN Padova)

“A Borcherds-Kac-Moody superalgebra with Conway symmetry”

Tue

29.05.

14:00

HIT E41.1

Yacine Ikhlef (Université Pierre et Marie Curie)

“Entanglement entropies of minimal models from null-vector equations”

abstract (click to view) We present a new method to compute Rényi entropies in one-dimensional critical systems. The null-vector conditions on the twist fields in the cyclic orbifold allow us to derive a differential equation for their correlation functions. The latter are then determined by standard bootstrap techniques. We apply this method to the calculation of various Rényi entropies in the non-unitary Yang-Lee model.
Joint work with B. Estienne and Th. Dupic (click to hide)