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)`

Regular Seminar Nadav Drukker (King's College London)

at:13:30
room H503 | abstract: In this talk I will reexamine the classification of BPS Wilson loops in 3d super Chern-Simons-matter theories. Over the last several years a large class of increasingly intricate constructions of such operators have been found. They involve both discrete and continuous parameters chosen to satisfy varied conditions. In my talk I will explain that the discrete parameters are related to choosing a graded quiver diagram, which may be a subquiver or a cover of the one defining the theory. The continuous parameters are then a singular limit of the variety, a complex manifold, associated to that quiver. |

Triangular Seminar Prem Kumar (Swansea)

at:16:00
room Huxley LT308 | abstract: I will describe thermodynamics and calculation of real time correlators in CFTs with extended W-symmetries, dual to AdS_3 gravity with a finite number of higher spin fields. I will point out mechanisms, including the appearance of a novel effective temperature, by which the proposed chaos bound due to Maldacena-Shenker-Stanford is violated in these theories. |

Triangular Seminar Geoffrey Compere (U Brussels)

at:17:30
room Huxley LT308 | abstract: I will first provide a bird-eye view upon the infrared structure of gravity. I will shortly describe the relationship between BMS symmetry, soft theorems and memory effects at leading and subleading orders in the large radius expansion, while emphasizing the specificities of super-Lorentz symmetries. Secondly, I will present a no-go result on the soft hair conjecture: supertranslations induced by matter creating and falling inside black holes do not affect Hawking radiation, though they do affect scattering amplitudes. I will start by proving that Unruh radiation is unaffected by supertranslations induced by a shockwave and then show that Hawking radiation is mathematically related to this system, as a consequence of the principle of equivalence. Third, I will explain how BMS symmetry is associated to flux-balance laws that provide constraints upon the motion of binary compact mergers. Finally, I will present the extension of the BMS group to asymptotically de Sitter spacetimes. |

Regular Seminar Noppadol Mekareeya (INFN Milan Bicocca and Chulalongkorn U)

at:13:00
room H503 | abstract: A local SL(2,Z) transformation on the Type IIB brane configuration gives rise to an interesting class of 3d superconformal field theories, known as the S-fold SCFTs. One of the interesting features of such a theory is that, in general, it does not admit a conventional Lagrangian description. Nevertheless, it can be described by a quiver diagram with a link being a superconformal field theory, known as the T(U(N)) theory. In this talk, we discuss various properties of the S-fold theories, including their supersymmetric indices, supersymmetry enhancement in the infrared, as well as several interesting dualities. |

Regular Seminar Stijn van Tongeren (Humboldt U)

at:14:00
room H503 | abstract: The TTbar deformation of two dimensional QFTs has various attractive and interesting features, giving a simple CDD deformation of the S matrix, and for instance preserving integrability, if present. As a simple example, deforming massless free scalars gives a Nambu-Goto string in flat space in a uniform light-cone gauge. I will discuss what happens if we deform "twice", i.e. TTbar deform light-cone gauge fixed string sigma models. In this setting, TTbar deformations can be viewed as TsT transformations in a suitable T dual frame. This TsT picture also gives a natural interpretation of the TTbar CDD factor as a Drinfeld-Reshetikhin twist. |

Regular Seminar Antonio Pittelli (Uppsala)

at:14:00
room H503 | abstract: We consider 4d N=1 gauge theories with R-symmetry on a hemisphere times a torus. We apply localization techniques to evaluate the exact partition function through a cohomological reformulation of the supersymmetry transformations. Our results represent the natural elliptic lifts of the lower dimensional analogs as well as a field theoretic derivation of the conjectured 4d holomorphic blocks, from which partition functions of compact spaces with diverse topology can be recovered through gluing. We also analyze the different boundary conditions which can naturally be imposed on the chiral multiplets, which turn out to be either Dirichlet or Robin-like. We show that different boundary conditions are related to each other by coupling the bulk to 3d N=1 degrees of freedom on the boundary three-torus, for which we derive explicit 1-loop determinants. |

Regular Seminar Henry Maxfield (UCSB)

at:14:00
room H503 | abstract: Semiclassical gravity is famously in tension with the unitary evolution of quantum mechanics when black holes evaporate. I'll describe a semiclassical calculation that nonetheless reproduces signatures of unitarity, namely the "Page curve" of entropy and the Hayden-Preskill protocol. This involves finding a quantum extremal surface, an extremum of the generalised entropy (the area in Planck units plus the entropy of exterior matter), which in the context of an evaporating black hole can exist far from a classical extremal surface. The calculations are performed in an exactly solvable model of Jackiw-Teitelboim gravity coupled to conformal matter. I will conclude by commenting and speculating on the implications for the information paradox. |