Imperial College has its own detailed information on general directions and on getting to the theoretical physics group. The College is located on Prince Consort Road, south of Hyde Park (map). The most convenient access is via tube (South Kensington, Gloucester Road) or buses. The Theoretical Physics group resides on the 5th floor of the Huxley Building. The group also possesses its own description.
Found at least 20 result(s)
Exceptional Seminar Antonio Pittelli (Surrey University)
at: 13:30 room H503  abstract: Dual superconformal symmetry is a remarkable, hidden feature of N=4 SYM in 4 dimensions. Via AdS/CFT, such a symmetry corresponds to the invariance of the AdS(5) x S(5) superstring under specific combinations of bosonic and fermionic Tdualities. We show that AdS(d) x S(d) x S(d) superstrings with D(2,1;\alpha) isometry supergroup are Tselfdual if additional Tdualities along complexified S(d) directions are performed. This implies that CFTs dual to AdS(d) x S(d) x S(d) x T(103d) superstrings enjoy a new type of dual superconformal symmetry. 
Exceptional Seminar Massimo Taronna (AEI)
at: 13:30 room H503  abstract: The aim of this talk is to extract the quadratic corrections to Fronsdal equations from Vasiliev's equations, and discuss their structure. The issue of locality in higherspin theories will be addressed. Implications of this analysis in relation to GiombiYin checks of higherspin/vector model duality will be discussed. Some of the previous puzzles will be resolved, while others will be elucidated. 
Regular Seminar Ehsan Hatefi (Queen Mary)
at: 14:00 room H503  abstract: We would like to talk about all kinds of supersymmetric and nonsupersymmetric scattering amplitudes of type IIA,IIB superstring theory as well as their corrections. In fact we want to address how to get to a universal conjecture for DBI, ChernSimons and more importantly new Wess Zumino actions with their all order $\alpha'$ corrections. Indeed we try to provide a comprehensive explanation even for D braneanti Dbrane systems, where various new techniques will be also introduced. If time allows , we then mention several issues related to those effective actions and eventually highlight some comments about higher point functions of the Mixed closed string RR , scalar fields in different pictures of the string theory amplitude. 
Regular Seminar Jose FernandezMelgarejo (Harvard)
at: 13:30 room H503  abstract: We study the general formulation of gauged supergravity in seven dimensions with sixteen supercharges keeping duality covariance by means of the embedding tensor formalism. We first classify all inequivalent duality orbits of consistent deformations. Secondly, we analyse the complete set of critical points in a systematic way. Interestingly, we find the first examples of stable de Sitter solutions within a theory with such a large amount of supersymmetry. 
Regular Seminar Branislav Jurco (Charles University/MPIM)
at: 14:00 room H503  abstract: We introduce connection, torsion and curvature for Courant algebroids. We discuss in detail torsionless connections compatible with a generalized metric and the related EinsteinHilbert actions. 
Regular Seminar Kazutoshi Ohta (Meiji Gakuin University)
at: 13:00 room H503  abstract: We derive the localization formula for N=4 supersymmetric quiver quantum mechanics in the Higgs and Coulomb branch. The partition function (index) is exactly evaluated and it is shown that the path integral is localized at fixed points, which are given by solutions to the BRST equations combined with Dterm and Fterm conditions. We give various examples of the quiver theory and classifications of their fixed points. The indexes completely agree with the mathematical wall crossing formulae for the quiver moduli spaces. We also discuss a gravitational picture of the localization in the Coulomb branch. 
Regular Seminar Peter Koroteev (PI)
at: 14:00 room H503  abstract:

Regular Seminar Babak Haghighat (Harvard)
at: 13:30 room H503  abstract: We consider bound states of strings which arise in 6d (1,0) SCFTs that are realized in Ftheory in terms of linear chains of spheres with negative selfintersections 1,2, and 4. These include the strings associated to N small E8 instantons, as well as the ones associated to M5 branes probing A and D type singularities in Mtheory or D5 branes probing ADE singularities in Type IIB string theory. We find that these bound states of strings admit (0,4) supersymmetric quiver descriptions and show how one can compute their elliptic genera. 
Regular Seminar Diego Hofman (UVA)
at: 15:00 room H503  abstract: Two dimensional Warped Conformal Field Theories (WCFTs) may represent the simplest examples of field theories without Lorentz invariance that can be described holographically. As such they constitute a natural window into holography in non AdS spacetimes, including the near horizon geometry of generic extremal black holes. I値l explain that WCFTs posses a type of boost symmetry. Using this insight, I値l discuss how to couple these theories to background geometry. This geometry is not Riemannian. We call it Warped Geometry and it turns out to be a variant of a NewtonCartan structure with additional scaling symmetries. With this formalism the equivalent of Weyl invariance in these theories will be discussed as well as examples of WCFTs. Lastly I値l present a systematic description of the holographic duals of WCFTs. I値l argue that the minimal setup is not Einstein gravity but an SL(2,R) x U(1) ChernSimons Theory, which we call Lower Spin Gravity. 
Regular Seminar Ayan Mukhopadhyay (CCTP and CCQCN, University of Crete)
at: 14:00 room H503  abstract: I will argue that the holographic correspondence can be reconstructed in the large N and strongly interacting limit as a specific generalisation of Wilsonian RG flow, which can be defined via three simple principles. I will also give an explicit example for such a reconstruction, where dual nonlinear classical gravity equations in the long wavelength approximation will emerge from specific kinds of coarse graining of hydrodynamics in the field theory. 
Regular Seminar Olalla Castro Alvaredo (City U.)
at: 14:00 room B1004  abstract: In this talk I will review some of the main results of my research in this area, which stated in 2007 in collaboration with John L. Cardy and Benjamin Doyon. I will emphasise how a special type of field we have named branch point twist field has become an essential tool for performing computations of the entanglement entropy in noncritical systems. I will show how the relationship between correlators of twist fields and entanglement entropy allows us to recover wellknown results for critical systems but also to predict new results for theories with a finite correlation length. Time permitting, I will mention some more recent results extending our understanding to nonunitary critical and noncritical systems. 
Regular Seminar David Berenstein (UCSB)
at: 13:30 room B1004  abstract: Half BPS states (operators) in N=4 SYM are famously described by free fermions both at weak and strong coupling. I describe a set of conjectures for a preferred class of states in more general conformal field theories that can be tested in supergravity for when such a free fermion description might arise and some motivation for it applying generally. The states in question belong to the chiral ring of a supersymmetric conformal field theory that extremize an additional U(1) charge for fixed dimension and can be reduced to multitraces of a composite matrix field, which is equivalent to using Young tableaux (Schur polynomials) as a basis. The main conjecture asserts that if the Young tableaux are orthogonal, then the set of extremal three point functions of traces to order 1/N are determined up to a single constant. The conjecture is extended further by providing an exact norm for the Schur basis and this norm arises from a set of free fermions for a generalized oscillator algebra. 
Regular Seminar Mario Flory (MaxPlanck Institute)
at: 15:30 room H503  abstract: My starting point is a holographic model of the Kondo effect recently proposed by Erdmenger et. al., i.e. of a magnetic impurity interacting with a strongly coupled system. Specifically, I focus on the challenges of computing gravitational backreaction in this model, which demands a study of the Israel junction conditions. I present general results on these junction conditions, including analytical solutions for certain toy models, that may be relevant also more generally in the AdS/boundary CFT correspondence. Furthermore, similar junction conditions for a bulk ChernSimons field appearing in the holographic Kondo model are discussed. I then focus on the computation and interpretation of entanglement entropy in this holographic model. 
Exceptional Seminar Evgeny Buchbinder (University of Western Australia)
at: 14:00 room H503  abstract:

Regular Seminar Paul Richmond (Oxford)
at: 14:00 room B1004  abstract: I will discuss how to construct rigid supersymmetric gauge theories on Riemannian fivemanifolds following a holographic approach. This approach realises the fivemanifold as the conformal boundary of a sixdimensional bulk supergravity solution and leads to a systematic classification of fivedimensional supersymmetric backgrounds with gravity duals. The background metric is furnished with a conformal Killing vector, which generates a transversely holomorphic foliation with a transverse Hermitian structure. Finally, I値l also construct supersymmetric Lagrangians for gauge theories coupled to arbitrary matter on such backgrounds. 
Regular Seminar Benjamin Assel (Kings College)
at: 14:00 room H503  abstract: I will discuss the partition function of 4d N=1 theories on Hopf surfaces. These are diffeomorphic to S^1 x S^3 and the partition function provides a path integral realization of the supersymmetric index. Its large S^1 limit exhibits a universal behaviour associated to the existence of a Casimir energy. I will argue that, contrarily to the nonsupersymmetric case, this Casimir energy is a physical (nonambiguous) quantity in supersymmetric theories. 
Regular Seminar Tomasz Lukowski (Oxford)
at: 14:00 room H503  abstract: In this talk I will discuss how to construct all solutions consistent with crossing symmetry in the limit of large central charge c ~ N^2, starting from the fourpoint correlator of the stress tensor multiplet in N=4 SYM. Unitarity forces the introduction of a scale \Delta_{gap} and these solutions organize as a double expansion in 1/c and 1/\Delta_{gap}. These solutions are valid to leading order in 1/c and to all orders in 1/\Delta_{gap} and reproduce, in particular, instanton corrections previously found. Comparison with such instanton computations allows to fix \Delta_{gap}. Using this gap scale one can explain the upper bounds for the scaling dimension of unprotected operators observed in the numerical superconformal bootstrap at large central charge. 
Regular Seminar Tristan Dennen (NBI)
at: 14:00 room H503  abstract: Supergravity theories were once hoped to provide ultraviolet finite theories of quantum gravity without requiring profoundly new physical frameworks. These hopes faded in the 1980s, but renewed efforts in recent years have uncovered some surprising ultraviolet behaviour. In this talk, I will give an overview of the explicit scattering amplitude calculations in perturbative supergravity over the last few years. In particular cases, there are indications of ultraviolet cancellations not accounted for by known symmetry arguments. I will highlight these cases and give some reasons to be optimistic and some reasons to be pessimistic about supergravity as a contender for a quantum theory of gravity. 
Regular Seminar Kostas Sfetsos (University of Athens)
at: 14:00 room H503  abstract: We review the construction of the socalled λdeformations of WZW and gauged WZW models. We discuss their integrability and algebraic properties, their behavior under RG flows as well as their embeddings to typeII supergravity. 
Exceptional Seminar Alfio Bonanno (INAF/INFN)
at: 12:00 room H503  abstract:
