Directions

We are located at the 6th floor of the G.O. Jones Building on the Mile End Campus, midway between Stepney Green and Mile End Tube stations, approximately 15-20 minutes from central London on the Central or District lines. If exiting Stepney Green tube station, turn left and walk along the Mile End Road for approximately 300 metres. The G.O. Jones (Physics) building is to the right of the main college building, which is fronted by a clocktower and lawn. If exiting Mile End tube station, turn left and walk approximately 300 metres until you are opposite the main college building. A more detailed description can be found here.

Seminars at Queen Mary University of London

Found at least 20 result(s)

21.04.2016 (Thursday)

Tachyonic Antibranes and the deSitter and Fuzzball Landscapes

Regular Seminar Iosif Bena (Saclay)

 at: 14:00 QMWroom G.O. Jones 610 abstract: Antibranes in backgrounds that have charge dissolved in fluxes are a key ingredient in constructing a landscape (Multiverse) of deSitter vacua in String Theory, and also of constructing microstate solutions corresponding to non-supersymmetric near-extremal black holes. There are several regimes of parameters in which one can study the physics of these antibranes, and I will show that in the regime of parameters where their gravitational backreaction is important, antibranes have a naked singularity that cannot be resolved either by brane polarization or by cloaking with a black hole horizon, and that signals a tachyonic instability. I will also present recent evidence that the theory on the wordvolume of anti-D3 branes is finite to all loops. I will conclude by discussing the implications of these results for the Multiverse paradigm and for the Fuzzball proposal.

14.04.2016 (Thursday)

Constraints on the CFT three point functions

Regular Seminar Manuela Kulaxizi (Trinity College Dublen)

 at: 14:00 QMWroom G.O. Jones 610 abstract: We discuss the energy flux constraints for conserved and non-conserved operators in an arbitrary higher dimensional CFT. We then consider a deep inelastic scattering thought experiment and show how to derive these and other bounds on the OPE coefficients of various operators.

07.04.2016 (Thursday)

Scrambling without chaos

Regular Seminar Alvaro Veliz Osorio (QMUL)

 at: 14:00 QMWroom G.O. Jones 610 abstract: We investigate measures of chaos and entanglement scrambling in rational conformal field theories in 1+1 dimensions. First, we derive a formula for the late time value of the out-of-time-order correlators for these class of theories. Our universal result can be expressed as a particular combination of the modular S-matrix elements known as anyon monodromy scalar. Next, in the explicit setup of a SU(N)k WZW model, we compare the late time behaviour of the out-of-time correlators and the purity. Interestingly, in the large-c limit, the purity grows logarithmically but the out-of-time-order correlators remain constant. Therefore, we find that some systems may display entanglement scrambling in the absence of chaos.

31.03.2016 (Thursday)

Bootstrapping N=2 SCFTs

Regular Seminar Madalena Lemos (DESY Hamburg)

 at: 14:00 QMWroom G.O. Jones 610 abstract: In this talk we will discuss the bootstrap program applied to four-dimensional N=2 superconformal field theories, with focus on analytical results. After a brief review of the protected subsector captured by a two-dimensional chiral algebra, we will show how analytic bounds on anomaly coefficients are obtained and constrain the space of allowed SCFTs. Finally we will comment the implications for the numerical bootstrap program.

10.03.2016 (Thursday)

3d N=2 dualities with monopoles

Regular Seminar Sara Pasquetti (Surrey U.)

 at: 14:00 QMWroom G.O. Jones 610 abstract: I will present several new 3d N=2 dualities with super-potentials involving monopole operators. Some of the theories that I will discuss describe systems of D3 branes ending on pq-webs. In these cases 3d mirror symmetry is a consequence of S-duality.

02.03.2016 (Wednesday)

Probing N=2 SUSY gauge theories with surface operators

Triangular Seminar Joerg Teschner (DESY)

 at: 15:00 QMWroom Maths Lecture Theatre abstract:

02.03.2016 (Wednesday)

Soft Hair on Black Holes

Triangular Seminar Malcolm Perry (DAMTP)

 at: 16:30 QMWroom Maths Lecture Theatre abstract:

18.02.2016 (Thursday)

Collabor8 - A Meeting for Early Career Researchers in Mathematical and Theoretical Physics

Exceptional Seminar Various Various (Various)

 at: 9:30 QMWroom GO Jones 610 abstract: Collabor8 is a day-long meeting for early career researchers in mathematical and theoretical physics on Thursday 18th February 2016. The purpose of the meeting is to encourage collaboration between PhD students and postdocs from different institutions and research specialisms working in the UK. The meeting will feature short presentations from selected speakers about ongoing research problems, in contrast to traditional longer seminars on completed work. These will form the basis of group discussions, where participants may share their expertise and suggest new approaches. The conference website provides a convenient social network to promote continuing interaction after the meeting. We are delighted that Professor Luis Fernando Alday will be delivering a keynote lecture at the meeting. There is no conference fee, and funds are available to reimburse travel expenses. Further information about the meeting, including the registration form, may be found on the website below. The deadline for registration is Thursday 4th February. http://www.collabor8research.org

11.02.2016 (Thursday)

Simplifying the Standard Model

Regular Seminar Paul Mansfield (Durham)

 at: 14:00 QMWroom G.O. Jones 610 abstract: I will show that the matter content of the Standard Model takes a simple form when expressed in terms of world-lines of spinning particles and set this in the context of an effective string theory of the Standard Model described by tensionless spinning strings with contact interactions.

28.01.2016 (Thursday)

Perturbative and numerical aspects of string sigma models

Regular Seminar Lorenzo Bianchi (DESY Hamburg)

 at: 14:00 QMWroom G.O. Jones 610 abstract: In the last fifteen years an extensive and successful program has been carried out, consisting in the application of integrability techniques to the study of the AdS/CFT correspondence in the planar limit. In this talk we focus on a particular string background corresponding, on the dual side, to the expectation value of a cusped Wilson line. Recently the study of this background has been boosted by the OPE program for polygonal Wilson loops and scattering amplitudes. In this talk we consider the quantum fluctuations of the worldsheet theory around the null cusp classical solution and we investigate various quantities of physical interest (free energy, dispersion relation, S-matrix) in the perturbative expansion at strong coupling. We also propose a possible discretization of this model which can be used to study the theory non-perturbatively through numerical lattice simulations.

14.01.2016 (Thursday)

Generalising Calabi-Yau for generic flux backgrounds

Regular Seminar Anthony Ashmore (Imperial College)

 at: 14:00 QMWroom G.O. Jones 610 abstract: Calabi-Yau manifolds without flux are perhaps the best-known supergravity backgrounds that leave some supersymmetry unbroken. The supersymmetry conditions on such spaces can be rephrased as the existence and integrability of a particular geometric structure. When fluxes are allowed, the conditions are more complicated and the analogue of the geometric structure is not well understood. In this talk, I will define the analogue of Calabi-Yau geometry for generic D=4, N=2 backgrounds with flux in both type II and eleven-dimensional supergravity. The geometry is characterised by a pair of G-structures in 'exceptional generalised geometry' that interpolate between complex, symplectic and hyper-Kahler geometry. Supersymmetry is then equivalent to integrability of the structures, which appears as moment maps for diffeomorphisms and gauge transformations. Similar structures also appear in D=5 and D=6 backgrounds with eight supercharges. As a simple application, I will discuss the case of AdS5 backgrounds in type IIB, where deformations of these geometric structures give exactly marginal deformations of the dual field theories.

10.12.2015 (Thursday)

Extremal black holes with wiggles

Regular Seminar Geoffrey Compere (ULB)

 at: 14:00 QMWroom G.O. Jones 610 abstract: Symmetries are crucial in physics. Here I will develop the concept of symplectic symmetry for Einstein gravity, which is an extension of the concept of asymptotic symmetries. I will then show that the throat of the extremal Kerr black hole admits symplectic symmetries, which leads to an infinite number of conserved charges which form a Virasoro algebra in 4 dimensions and a novel generalized Virasoro algebra in higher dimensions. I will build explicitly the geometries that carry these charges, the so-called "descendants" of the extremal black hole, in the near-horizon region.

07.12.2015 (Monday)

Student Triangle Gong Show

Triangular Seminar Gong Show (IC/KCL/CU/QMUL)

 at: 15:00 QMWroom LG1 abstract: Student Triangles are a chance for PhD students to give talks to their fellow PhD students from the London Universities, without the pressure of presenting in front of academics. For this first student triangle of the year we will be holding a gong show with a series of short whiteboard talks. PhD students can sign up for a gong show slot on http://doodle.com/poll/ehgri6kz6f6a8cux

26.11.2015 (Thursday)

Regular Seminar Yang-Hui He (City)

 at: 14:00 QMWroom G.O. Jones 610 abstract: We study the web of correspondences linking the exceptional Lie algebras E8,7,6 and the sporadic simple groups Monster, Baby and the largest Fischer group. We will survey some old observations from the perspective of Moonshine and representation theory and present some new ones from that of congruence groups and enumerative geometry. Based on joint work with John McKay.

19.11.2015 (Thursday)

5d theories on curved backgrounds, Yang-Mills deformations and instantons

Regular Seminar Diego Rodriguez-Gomez (Universidad de Oviedo)

 at: 14:00 QMWroom G.O. Jones 610 abstract: 5d theories can be at fixed points, in many cases exhibiting rather amusing properties. In this talk we will study several properties of these fixed point theories. In particular, we will describe how to put them supersymmetrically in curved spaces. As a consequence, we will discuss when a deformation to a Yang-Mills theory is possible. The latter typically exhibit a smaller global symmetry that that of the fixed point theory, which, from the YM point of view, appears as an enhanced symmetry. In this enhancement instantons play a pivotal role, and we will discuss several aspects of these.

18.11.2015 (Wednesday)

Polygon Seminar: An introduction to the Hilbert series as operator counting

Triangular Seminar Diego Rodriguez-Gomez (University of Oviedo)

 at: 15:00 QMWroom GO Jones 610 abstract: Counting operators in supersymmetric field theories is very interesting, as the corresponding generating functions encode properties of the field theory. In this lecture we will mostly concentrate on 4d SUSY field theories. After reviewing some basic notions about SUSY field theories leading to the notion of chiral ring, we will introduce a generating function enumerating operators in the ring. This function is the so-called Hilbert series. In the case of SCFTs with a gravity dual, we will show how this function recovers geometric properties of the dual gravity background. The uses of the Hilbert series go beyond this, since, as we will see, being a counting of operators, it is of relevance in the computation of instanton partition functions for pure gauge theories. In the second part of the lecture we will briefly touch upon these issues.

12.11.2015 (Thursday)

Exact Results for Entanglement and Renyi Entropies, and their Gravity Duals

Regular Seminar Julian Sonner (University of Geneva)

 at: 14:00 QMWroom G.O. Jones 610 abstract: The recent focus on entanglement entropy in holography has many motivations, ranging from the applied (e.g. AdS/CMT) to the foundational (emergence of gravity). For all of these programs It is important to find examples, where the quantities of interest can be directly calculated in strongly-coupled field theories and, moreover, the dual geometry constructed at strong coupling. In this talk I will describe joint work with Crossley and Dyer on using localization methods to obtain entanglement and (super-) Renyi entropies of the N=4 SYM theory with gauge group SU(N) in 4D at all values of the ’t Hooft coupling \lambda and number of colors N. Since obtaining quantities like entanglement and Renyi entropies involves working on singular spaces, which typically break the supersymmetry, we focus on a supersymmetric generalization, the so-called super-Renyi entropy where the supersymmetry breaking effects of the singularities are suitably compensated. I will also discuss dual gravity solutions as five-dimensional BPS black holes with hyperbolic horizon. I will conclude with a description of Wilson loops, that is the contribution to the entanglement and Renyi entropies due to adding fundamental matter to the theory.

11.11.2015 (Wednesday)

Graduate Lectures: A first introduction to string amplitudes III

Informal Seminar Rodolfo Russo (Queen Mary)

 at: 10:00 QMWroom GO Jones 610 abstract: Lecture 3: An example of mixed open/closed amplitudes

10.11.2015 (Tuesday)

Graduate Lectures: A first introduction to string amplitudes II

Informal Seminar Rodolfo Russo (Queen Mary)

 at: 10:00 QMWroom GO Jones 610 abstract: Lecture 2: Derivation of the Virasoro-Shapiro amplitude; 4 graviton amplitude in the superstring (no derivation, but discussion of the low and high energy limits)

02.11.2015 (Monday)

Graduate Lectures: A first introduction to string amplitudes I

Informal Seminar Rodolfo Russo (Queen Mary)

 at: 10:00 QMWroom GO Jones 610 abstract: Lecture 1: Veneziano amplitude: derivation, low and high energy limits