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 Noppadol Mekareeya (INFN Milan Bicocca and Chulalongkorn U)
at: 14:00 room H503  abstract:

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 NambuGoto string in flat space in a uniform lightcone gauge. I will discuss what happens if we deform "twice", i.e. TTbar deform lightcone 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 DrinfeldReshetikhin twist. 
Regular Seminar Antonio Pittelli (Uppsala)
at: 14:00 room H503  abstract: We consider 4d N=1 gauge theories with Rsymmetry 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 Robinlike. 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 threetorus, for which we derive explicit 1loop 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 HaydenPreskill 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 JackiwTeitelboim gravity coupled to conformal matter. I will conclude by commenting and speculating on the implications for the information paradox. 
Regular Seminar Panos Betzios (Crete)
at: 14:00 room H503  abstract: In this talk I will discuss asymptotically AdS wormhole solutions in the context of holography. I will present how to compute correlation functions of local operators as well as non local observables such as correlation functions of Wilson loops on the distinct boundaries and I will discuss their behavior. Moreover, I will discuss the effect that multitrace deformations have on such observables. From the computations mentioned we observe that the dual theory is expected to be described in terms of two interacting sectors coupled by a UV soft, nonlocal interaction. Finally, I will present a simple effective field theory construction that can explain the behaviors that we observe from these gravitational computations. 
Regular Seminar Francesco Benini (SISSA)
at: 14:00 room H503  abstract: AdS/CFT provides a consistent nonperturbative 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) SuperYangMills, with the help of a new Bethe Ansatz type formula, we are able to exactly reproduce the BekensteinHawking entropy of BPS black holes in AdS5 x S5. The large N limit exhibits many competing contributions and Stokes phenomena, hinting at new physics. 
Regular Seminar Andrey Gromov (Brown)
at: 13:30 room H503  abstract: Fractional quantum Hall (FQH) states are topologically ordered. Additionally, FQH states support a collective neutral excitation known as the GirvinMacDonaldPlatzman (GMP) mode. Certain features of this mode are independent of the microscopic details. The objective of the talk is to construct an effective theory includes both topological properties and the massive GMP mode. The theory reproduces the universal properties of chiral lowest Landau level (LLL) FQH states which lie beyond the TQFT data, such as the projected static structure factor and the GMP algebra of areapreserving diffeomorphisms. The dynamics of the mode is described by a fluctuating rank2 symmetric, positivedefinite tensor, which leads to a natural geometric (or gravitational) interpretation of the GMP mode. 
Regular Seminar Emil Martinec (Chicago)
at: 14:00 room H503  abstract: The microstate structure of AdS3 black holes involves stringy ingredients, yet quantitative control over these ingredients in a regime where the state being described approximates a black hole has been elusive. This talk will show how 2d worldsheet current algebra provides a tool to describe the stringy objects that govern the black hole phase transition in AdS3 and linear dilaton backgrounds, providing a bridge between the entropycarrying degrees of freedom of the dual nongravitational theory (little strings or long strings) and their conjectured gravitational dual, the fuzzball. 
Regular Seminar Olaf Hohm (Humboldt, Berlin)
at: 14:00 room H503  abstract: I discuss the higherderivative \alpha' corrections in the reduction to one dimension (cosmic time) that is relevant for the dynamics of cosmological backgrounds. In this setting string theory is known to be duality invariant under O(d,d), which makes it possible to completely classify all \alpha' corrections. I discuss some generic features of the \alpha' completed Friedmann equations and show that there are duality invariant theories that allow for de Sitter solutions that are nonperturbative in \alpha', suggesting that string theory may permit de Sitter vacua in this novel fashion. 