## Directions

This institute may be found at Strand in Central London, just north of the Thames (map).

Getting to the Strand Campus:

• #### By underground

Temple (District and Circle lines): 2 minute walk. Charing Cross (Bakerloo and Northern lines): 10 minute walk, Embankment (District, Circle and Bakerloo lines): 10 minute walk, Waterloo (Jubilee, Northern, Bakerloo, Waterloo & City lines): 12 minute walk, Holborn (Central and Picadilly lines): 12 minute walk,Chancery Lane (Central line): use exit 4 - 15 minute walk.

• #### By train

Charing Cross: 9 minute walk. Waterloo: 12 minute walk. Waterloo East: 10 minute walk. Blackfriars: 12 minute walk.

• #### By bus

Buses stopping outside the College: 1, 4, 26, 59, 68, 76, X68, 168, 171, 172, 176(24 hour), 188, 243 (24 hour), 341 (24 hour), 521, RV1.

## Seminars at King's College London

Found at least 20 result(s)

### 30.10.2019 (Wednesday)

#### Triangular Seminar at KCL

Triangular Seminar TBA TBA (CERN)

 at: 16:00 KCLroom TBA abstract:

### 10.04.2019 (Wednesday)

#### Black holes in N=4 Super-Yang-Mills

Regular Seminar Francesco Benini (SISSA, Trieste)

 at: 13:15 KCLroom S2.49 abstract: AdS/CFT provides a consistent non-perturbative definition of quantum gravity in asymptotically AdS space. Black holes should correspond to ensembles of states in the boundary field theory. By analyzing the superconformal index of 4d N=4 SU(N) Super-Yang-Mills, with the help of a new Bethe Ansatz type formula, we are able to exactly reproduce the Bekenstein-Hawking entropy of BPS black holes in AdS5 x S5. The large N limit exhibits many competing contributions and Stokes phenomena, hinting at new physics.

### 27.03.2019 (Wednesday)

#### Bootstrapping Inflationary Fluctuations

Regular Seminar Guilherme Leite Pimentel (University of Amsterdam)

 at: 13:15 KCLroom S2.49 abstract: In flat space, four point scattering amplitudes at weak coupling can be fully determined from Lorentz symmetry, unitarity and causality. The resulting scattering amplitude depends on model details only through coupling constants and the particle content of the theory. I will show how the analogous story works in the case of inflationary fluctuations. We found explicit expressions for inflationary three and four-point functions, whose shapes depend on the field content of the theory, and do not depend on the specific inflationary model, as long as the fluctuations minimally break de Sitter symmetry. This cosmological bootstrap” is a first step towards classifying all possible shapes of primordial non-gaussianity, which can be searched for in experimental data.

### 20.03.2019 (Wednesday)

#### 3d Abelian Gauge theories at the Boundary

Regular Seminar Edoardo Lauria (University of Durham)

 at: 13:15 KCLroom S2.49 abstract: A four-dimensional abelian gauge theory can be coupled to a 3d CFT with a U(1) symmetry living on a boundary. This coupling gives rise to a continuous family of boundary conformal field theories (BCFTs) parametrized by the gauge coupling \tau and by the choice of the CFT in the decoupling limit. Upon performing an Electric-Magnetic duality in the bulk and going to the decoupling limit in the new frame, one finds a different 3d CFT on the boundary, related to the original one by Witten's SL(2, Z) action. In particular the cusps on the real \tau axis correspond to the 3d gauging of the original CFT. We study general properties of this family of BCFTs. We show how to express bulk one and two-point functions, and the hemisphere free-energy, in terms of the two-point functions of the boundary electric and magnetic currents. Finally, upon assuming particle-vortex duality (and its fermionic version), we show how to turn this machinery into a powerful computational tool to study 3d gauge theories.

### 13.03.2019 (Wednesday)

#### Anomalous supersymmetry

Regular Seminar Marika Taylor (University of Southampton)

 at: 13:15 KCLroom S-1.04 abstract: We show that supersymmetry is anomalous in N = 1 superconformal quantum field theories (SCFTs) with an anomalous R-symmetry. This anomaly was originally found in holographic theories: here we show that this anomaly is present in general and demonstrate it for the massless superconformal Wess-Zumino model via a one loop computation of four-point functions of two supercurrents with either R-currents. In fact, the Wess-Zumino consistency conditions together with the standard R-symmetry anomaly imply the existence of the anomaly. We outline the implications of this anomaly.

### 07.03.2019 (Thursday)

#### The Cosmological Constant and the Electroweak Scale

Regular Seminar Henry Tye ()

 at: 15:00 KCLroom S7.06 abstract: KCL TPPC Seminar

### 06.03.2019 (Wednesday)

#### When black holes collide: Probing the quantum state of black holes by the spectrum of emitted gravitational waves

Regular Seminar Ramy Brustein (Ben-Gurion University (Israel))

 at: 15:15 KCLroom K6.63 abstract: KCL TPPC Seminar Abstract: Black hole (BH) mergers can be viewed as cosmological “scattering experiments” resulting in an excited BH, which then decays to its ground state by emitting gravitational waves (GW). I will present general arguments, based on fundamental physics principles, as to why we should expect additional quantum ringdown modes to those predicted by general relativity. Then, I will discuss the spectrum of the predicted ringdown modes, the resulting emitted GW and the prospects for their detection in LIGO/VIRGO.

### 27.02.2019 (Wednesday)

#### Massive AdS Gravity from String Theory

Regular Seminar Costas Bachas (Ecole Normale Superieure)

 at: 13:15 KCLroom S2.49 abstract: TBA

### 21.02.2019 (Thursday)

#### L_infinity algebras, the BV formalism, and Classical Fields

Exceptional Seminar Martin Wolf (Surrey)

 at: 11:00 KCLroom Bush House S 2.01 abstract: I will first review the Batalin-Vilkovisky formalism and its mathematical foundations with an emphasis on higher algebraic structures and classical field theories. I will then move on and discuss recent developments in formulating higher gauge theory with Lie quasi-groupoids as gauge structure. Finally, I will explain how all these ideas can be combined with those of twistor theory to formulate maximally superconformal gauge theories in four and six dimensions by means of quasi-isomorphisms.

### 21.02.2019 (Thursday)

#### Twisting and localization in supergravity: equivariant cohomology of BPS black holes

Exceptional Seminar Imtak Jeon (KCL)

 at: 11:50 KCLroom Bush House S 2.01 abstract: I will talk about the formalism of supersymmetric localization in supergravity using the deformed BRST algebra defined in the presence of a supersymmetric background. The gravitational functional integral localizes onto the cohomology of a global supercharge Qeq, obeying (Qeq)2=H, where H is a global symmetry of the background. This construction naturally produces a twisted version of supergravity whenever supersymmetry can be realized off-shell. I will present the details of the twisted graviton multiplet and ghost fields for the superconformal formulation of four-dimensional N=2 supergravity. As an application of our formalism, we systematize the computation of the exact quantum entropy of supersymmetric black holes. In particular, we compute the one-loop determinant of the Qeq deformation operator for the off-shell fluctuations of the Weyl multiplet around the AdS2×S2 saddle.

### 21.02.2019 (Thursday)

#### 3d Abelian Gauge theories at the Boundary

Exceptional Seminar Edoardo Lauria (Durham)

 at: 14:00 KCLroom Bush House S 2.01 abstract: A four-dimensional abelian gauge theory can be coupled to a 3d CFT with a U(1) symmetry living on a boundary. This coupling gives rise to a continuous family of boundary conformal field theories (BCFTs) parametrized by the gauge coupling τ and by the choice of the CFT in the decoupling limit. Upon performing an Electric-Magnetic duality in the bulk and going to the decoupling limit in the new frame, one finds a different 3d CFT on the boundary, related to the original one by Witten's SL(2, Z) action. In particular the cusps on the real τ axis correspond to the 3d gauging of the original CFT. We study general properties of this family of BCFTs. We show how to express bulk one and two-point functions, and the hemisphere free-energy, in terms of the two-point functions of the boundary electric and magnetic currents. Finally, upon assuming particle-vortex duality (and its fermionic version), we show how to turn this machinery into a powerful computational tool to study 3d gauge theories.

### 21.02.2019 (Thursday)

#### Entanglement Content of Quantum Particle Excitations

Exceptional Seminar Cecilia De Fazio (City)

 at: 14:50 KCLroom Bush House S 2.01 abstract: In the ﬁrst part of my talk I will give a brief introduction to the main features of the Entaglement Entropy of a bipartite system in Integrable Quantum Field Theories and Conformal Field Theories. Secondly I will discuss the results my collaborators and I obtained in our two papers. In particular, I will consider the Entaglement Entropy of a single connected region of a ﬁnite bipartite system in excited states described by one-dimensional massive free theories with ﬁnite numbers of particles. I will show that in the limit of large volume and large length of the region the excess of entanglement due to the presence of the particles with respect to the ground state takes a simple form and admits a "q-bit interpretation".

### 21.02.2019 (Thursday)

#### Thermo/HydroDynamics of the classical Toda system and random matrix theory

Exceptional Seminar Benjamin Doyon (KCL)

 at: 16:00 KCLroom Bush House S 2.01 abstract: This will be presenting mainly some of my recent work, and also aspects of recent work of Herbert Spohn, both developed in parallel. The classical Toda system is a one-dimensional integrable many-body system, which can be seen either as a gas of particles or as a chain of degrees of freedom. Herbert has shown how the generalised Gibbs ensembles of the Toda chain can be obtained from a certain limit of the beta-ensemble in random matrix theory. Analysing and connecting the gas and chain viewpoints, I have obtained both the generalised Gibbs ensembles and generalised hydrodynamics from a quasiparticle scattering description. Thus we make a connection between quasiparticle scattering and random matrix theory.

### 20.02.2019 (Wednesday)

#### Witten, Cardy, and the Holonomy Saddle

Polygon Seminar Piljin Yi (KIAS)

 at: 15:00 KCLroom S-1.27 abstract: This talk will explore topological invariants of susy gauge theories, with some emphasis on index-like quantities and the notion of holonomy saddles. We start with 1d refined Witten index computations where the twisted partition functions typically show rational, rather than integral, behavior. We will explain how this oddity is a blessing in disguise and propose a universal tool for extracting the truely enumerative Witten indices. In part, this finally put to the rest a two-decade-old bound state problems which had originated from the M-theory hypothesis. Along the way, we resolve an old and critical conflict between Kac+Smilga and Staudacher/Pestun, circa 1999~2002, whereby the notion of holonomy saddles emerges and plays a crucial role. More importantly, the holonomy saddle prove to be universal features of supersymmetric gauge theories when the spacetime include a small circle. We explore them further for d=4, N=1 theories, with much ramifications on recent claims on Cardy exponents of their partition functions.

### 13.02.2019 (Wednesday)

#### String theory compactifications with sources

Regular Seminar Alessandro Tomasiello (Universita di Milano-Bicocca)

 at: 13:15 KCLroom S2.49 abstract: In recent years, more and more compactifications have emerged whose existence depends crucially on the presence of internal sources to the supergravity fields, such as D-branes and orientifold planes. I will review some solutions of this type in various dimensions, and illustrate their applications to holography and potentially to the problem of finding de Sitter solutions.

### 04.02.2019 (Monday)

#### Single trace TTbar-deformations and AdS/CFT

Informal Seminar Gaston Giribet (UBA)

 at: 10:00 KCLroom K6.63 abstract: A solvable irrelevant deformation of AdS3/CFT2 correspondence leading to a theory with Hagedorn spectrum at high energy has been recently proposed by Kutasov et al. It consists of a single trace deformation of the boundary theory, which is inspired by the recent work on solvable T\bar{T}-deformations of two-dimensional CFTs. Thought of as a worldsheet sigma-model, the interpretation of the deformed theory from the bulk viewpoint is that of string theory on a background that interpolates between AdS3 in the IR and a linear dilaton vacuum of little string theory in the UV. In this talk, after giving an introduction to this class of solvable theories, I will present explicit results for their observables.

### 30.01.2019 (Wednesday)

#### Cosmic censorship violation and black hole collisions in higher dimensions

Regular Seminar Roberto Emparan (ICREA, Barcelona)

 at: 13:15 KCLroom S2.49 abstract: The cosmic censorship conjecture raises the question of whether classical gravitational dynamics can drive a low-energy configuration into an accessible regime of quantum gravity, with Planck-scale curvatures and energy densities visible by distant observers. I will present evidence that cosmic censorhip is violated in the quintessential phenomenon of General Relativity: the collision and merger of two black holes. It only requires a sufficient total angular momentum in a collision in high enough number of dimensions. Nevertheless, I will argue that even if cosmic censorship is violated in this and in some other know instances, its spirit remains unchallenged: classical relativity describes the physics seen by observers outside the black holes accurately, with only minimal quantum input that does not entail macroscopic disruptions.

### 23.01.2019 (Wednesday)

#### What spatial geometry does the (2+1)-d QFT vacuum prefer?

Regular Seminar Toby Wiseman (Imperial College London)

 at: 13:15 KCLroom S2.49 abstract: We consider the energy of a (2+1)-d relativistic QFT on a deformation of flat space in either the quantum or thermal vacuum state. Looking at both free scalars and fermions, with and without mass (and in the scalar case including a curvature coupling) we surprisingly find that any deformation of flat space is always energetically preferred to flat space itself. This is a UV finite effect, insensitive to any cut- off. We see the same behaviour for any (2+1)-holographic CFT which we compute via the gravity dual. We consider the physical application of this to membranes carrying relativistic degrees of freedom, the vacuum energy of which then induce a tendency for the membrane to crumple. An interesting case is monolayer graphene, which experimentally is observed to ripple, and on large scales can be understood as a membrane carrying free massless Dirac degrees of freedom.

### 12.12.2018 (Wednesday)

#### An Etude on 3d N=2 Conformal Manifolds

Regular Seminar Nikolay Bobev ( KU Leuven)

 at: 13:15 KCLroom S2.49 abstract: I will describe the one-dimensional complex conformal manifold that controls the infrared dynamics of a three-dimensional N=2 supersymmetric theory of three chiral superfields with a cubic superpotential. Two special points on this conformal manifold are the XYZ model and three decoupled copies of the critical Wess-Zumino model. The conformal manifold enjoys a discrete duality group and can be thought of as an orbifold of CP^1. I will discuss how to compute the spectrum of low lying operators and their OPE coefficients as a function of the coordinate on the conformal manifold using the epsilon-expansion and the numerical conformal bootstrap.

### 04.12.2018 (Tuesday)

#### Coulomb branches and mock modular forms

Informal Seminar Giorgios Korpas (Trinity College, Dublin)

 at: 10:15 KCLroom K6.63 abstract: “We revisit Donaldson-Witten theory, that is the N=2 topologically twisted super Yang-Mills theory with gauge group SU(2) or SO(3) on compact 4-manifolds. We study the effective action in the Coulomb branch of the theory and by considering a specific Q-exact deformation to the theory we find interesting connections to mock modular forms. A specific operator of this theory computes the famous Donaldson invariants and our analysis makes their computation more accessible than previously. We also extend these ideas to the case of ramified Donaldson-Witten theory, that is the theory in the presence of embedded surfaces. Our results make calculations of correlation functions of Coulomb branch operators more trackable and we hope that they can help in the search of new 4-manifold invariants.”