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)

24.05.2018 (Thursday)

Positivity Constraints in Effective Field Theories

Regular Seminar Andrew Tolley (Imperial College London)

at:
14:00 QMW
room G O Jones 610
abstract:

I will review how the requirements of unitarity, locality, causality and Lorentz invariance impose constraints on the signs of the operator coefficients in an effective field theory, discuss recent work on generalizing these constraints to arbitrary spin particles, and discuss how these can be used to constrain gravitational EFTs of the type considered by cosmologists as models for dark energy or inflation.

17.05.2018 (Thursday)

tba

Regular Seminar Suresh Nampuri (Lisbon IST)

at:
14:00 QMW
room G O Jones 610
abstract:

10.05.2018 (Thursday)

Non-Abelian T-duality in AdS/CFT: the CFT side

Regular Seminar Yolanda Lozano (Oviedo U.)

at:
14:00 QMW
room G O Jones 610
abstract:

Non-Abelian T-duality, a transformation in String Theory known since the 90’s, has been shown recently to be a powerful solution generating technique in supergravity. In this talk I will discuss various AdS backgrounds generated through this transformation, for which it is possible to give a dual CFT interpretation arising from Hanany-Witten brane set-ups.

26.04.2018 (Thursday)

The different guises of elliptic Feynman integrals

Regular Seminar Claude Duhr (Cern)

at:
14:00 QMW
room G O Jones 610
abstract:

The computation of Feynman integrals is an important ingredient to compute scattering amplitudes to higher orders in perturbative QFT. Over the last couple of years, a lot of progress was made in understanding the mathematics of multi-loop Feynman integrals. In particular, it was understood that large classes of integrals evaluate to a class of special functions called multiple polylogarithms, which are an object of active research also in pure mathematics. It is known that starting from two loop, generalisations of polylogarithms to elliptic curves can show up. In this talk we review certain classes of elliptic multiple polylogarithms, and we show that they are closely related to iterated integrals on certain modular curves.

19.04.2018 (Thursday)

Cluster algebras, integrability and scattering amplitudes

Regular Seminar Georgios Papathanasiou (DESY)

at:
14:00 QMW
room G O Jones 610
abstract:

I present recent progress towards determining the planar S-matrix of maximally supersymmetric Yang-Mills theory, thanks to the rich interplay between its perturbative analytic properties in general kinematics, and its integrable structure in special kinematics. The former are related to cluster algebras, and allow for the computation of amplitudes with six/seven gluons up to six/four loops, whereas the latter yields all amplitudes in the multi-Regge limit at finite coupling.

18.04.2018 (Wednesday)

Feynman Integrals: symmetries and seagulls

Regular Seminar Ruth Shir (Hebrew University of Jerusalem)

at:
16:00 QMW
room G O Jones 610
abstract:

Feynman diagrams will be looked at from a new point of view. 'Symmetries of Feynman Integrals' is an analytical method for calculating Feynman diagrams. It is based on exposing an underlying group structure of a given diagram which defines a set of partial differential equations in the parameter space of the diagram. Group orbits in the diagram’s parameter space are used to reduce the Feynman integral into a line integral. The vacuum seagull, a three-loop diagram, and the propagator seagull, a propagator-type diagram with two loops, will be used to demonstrate the method, and to obtain new results.

28.03.2018 (Wednesday)

A new twist on toroidal string compactifications

Regular Seminar Mariana Grana (IPhT Saclay)

at:
14:00 QMW
room G O Jones 610
abstract:

TBA

22.03.2018 (Thursday)

On the scaling limit of the integer quantum Hall plateau transition

Regular Seminar Martin Zirnbauer (University of Cologne)

at:
14:00 QMW
room G O Jones 610
abstract:

The scaling behavior near the transition between plateaus of the integer quantum Hall effect has traditionally been interpreted on the basis of a two-parameter renormalization group flow conjectured from the non-linear sigma model of Pruisken. Yet, this scaling picture never led to any analytical understanding of the critical point. Here we propose a novel description of the critical point as Pruisken's nonlinear sigma model coupled to a maximally gauged Wess-Zumino-Witten model of level 4. This proposal explains the existing numerical data for the multifractal scaling exponents of critical wavefunctions.

15.03.2018 (Thursday)

Conformal bootstrap at large charge

Regular Seminar Daniel Jafferis (Harvard U.)

at:
14:00 QMW
room G O Jones 610
abstract:

07.03.2018 (Wednesday)

Triangle Seminar--Aristotelian QFT, Supersymmetry and Naturalness

Triangular Seminar Petr Horava (UC Berkeley)

at:
15:00 QMW
room Peoples Palace PP01
abstract:

22.02.2018 (Thursday)

Knot Invariants and M theory

Regular Seminar Radu Tatar (Liverpool U.)

at:
14:00 QMW
room G O Jones 610
abstract:

Brane construction with certain boundary conditions are used to study knot invariants and Khovanov homology. We argue that seven-dimensional manifolds in M-theory give rise to the topological theories may appear from certain twisting of the G-flux action. We discuss explicit constructions of the seven-dimensional manifolds in M-theory, and show that both the localization equations and surface operators appear naturally from the Hamiltonian formalism of the theories. Knots and link invariants are then constructed using M2-brane states in both the models.

15.02.2018 (Thursday)

Exceptional geometry for affine and other groups

Regular Seminar Axel Kleinschmidt (MPI Potsdam)

at:
14:00 QMW
room G O Jones 610
abstract:

Exceptional geometry is an attempt to combine the geometric diffeomorphisms and matter gauge transformations in gravity-matter theories into a single geometric structure. I will review recent results associated with a 2+9 split of maximal supergravity where the affine symmetry group E9 plays a central role. The results also provide a general formula that is applicable to many other cases.

14.02.2018 (Wednesday)

Differential equations for loop integrals without squared propagators

Regular Seminar Kasper Larsen (U. Southampton)

at:
14:00 QMW
room G O Jones 610
abstract:

A powerful approach to compute multi-loop Feynman integrals is to reduce the integrals to a basis of integrals and set up a first-order linear system of partial differential equations for the basis integrals. In this talk I will discuss the differential equations that arise when the loop integrals are parametrized in Baikov representation. In particular, I give a proof that dimension shifts (which are undesirable) can always be avoided. I will moreover show that in a large class of two- and three-loop diagrams it is possible to avoid integrals with squared propagators in the intermediate stages of setting up the differential equations. This is interesting because it implies that the differential equations can be set up using a smaller set of reductions.

01.02.2018 (Thursday)

The Search for the Exotic: Subfactors and Conformal Field Theory

Regular Seminar David Evans ()

at:
14:00 QMW
room G O Jones 610
abstract:

I will discuss the programme to understand conformal field theory via subfactors and twisted equivariant K-theory. This has also resulted in a better understanding of the double of the Haagerup subfactor, which was previously thought to be exotic and un-related to known models.

25.01.2018 (Thursday)

The Yang-Mills origin of all homogeneous N=2 supergravities

Regular Seminar Alexandros Anastasiou (NORDITA)

at:
14:00 QMW
room G O Jones 610
abstract:

Squaring involves the tensoring between the state content of two super Yang-Mills (sYM) theories to obtain the state content of a supergravity theory. Understanding the YM origin of gravitational symmetries is a powerful tool towards classifying gravity theories which admit such a factorisation. In the first part of the talk I will show how the global symmetries of a pair of sYM theories combine to form those of the corresponding supergravity. In the second part I will discuss how these tools can be further extended to sYM coupled to matter such that squaring can give all ungauged N=2 supergravities with homogeneous scalar manifold.

18.01.2018 (Thursday)

Numerical Simulations of Asymptotically AdS Spacetimes

Regular Seminar Hans Bantilan (QMUL)

at:
14:00 QMW
room G O Jones 610
abstract:

The main purpose of this talk is to describe, by way of concrete examples, how the field of numerical relativity now contributes to our understanding of open questions in gravitational collapse, heavy-ion physics, and turbulence. I will begin by motivating these studies in terms of the physical systems they are intended to clarify,then provide specific examples of how to describe these systems with numerical simulations of asymptotically AdS spacetimes in the fully non-linear regime of general relativity.

11.01.2018 (Thursday)

Spacetime as a resource

Regular Seminar Joan Simon (U. of Edinburgh)

at:
14:00 QMW
room G O Jones 610
abstract:

The relation between black holes and thermodynamics leading to the holographic principle is well known. Formulating thermodynamics as the theory of transformations performing some work or task allows us to reinterpret recent developments in AdS/CFT, such as the holographic description of entanglement entropy, as a measure of the connectivity of space (resource). Whether spacetime in the interior of a black hole also allows an understanding as a resource is an interesting open question.

14.12.2017 (Thursday)

Branes and the Kraft-Procesi transition

Regular Seminar Santiago Cabrera Marquez (Imperial College London)

at:
14:00 QMW
room G O Jones 610
abstract:

Type IIB superstring brane configurations can have a low energy dynamics described by an effective 3d N=4 gauge theory. The moduli space of the gauge theory is normally a Hyperkähler variety. Singular points in the variety correspond to brane configurations where some fields become massless, giving rise to the Higgs mechanism. I will explain the relevance of a set of theories whose moduli space is the closure of a nilpotent orbit of Lie(F), where F is the flavour symmetry group of the theory. I will show how the mathematical description of the "transverse slice" between two nilpotent orbits can be understood in terms of brane dynamics as a realisation of the Higgs mechanism.

08.12.2017 (Friday)

Graduate Mini-course: Holographic combinatorics : 2d Yang Mills theory to tensor models via AdS/CFT

Triangular Seminar Sanjaye Ramgoolam (QMUL)

at:
11:00 QMW
room GO Jones 610
abstract:

These lectures will be focused on aspects of combinatorics relevant to gauge-string duality (holography). The physical theories we will discuss include two dimensional Yang Mills theory, four-dimensional N=4 super Yang Mills theory with U(N) gauge group, Matrix and tensor models. The key mathematical concepts include : Schur Weyl-duality, permutation equivalence classes and associated discrete Fourier transforms as an approach to counting problems and, branched covers and Hurwitz spaces. Schur-Weyl duality is a powerful relation between representations of U(N) and representations of symmetric groups. Representation theory of symmetric groups offers a method to define nice bases for functions on equivalence classes of permutations. These bases are useful in counting gauge invariant functions of matrices or tensors, as well as computing their correlators in physical theories. In AdS/CFT these bases have proved useful in identifying local operators in gauge-theory dual to giant gravitons in AdS. In the simplest cases of gauge-string duality, the known mathematics of branched covers and Hurwitz spaces provide the mechanism for the holographic correspondence between gauge invariants and stringy geometry. (Lecture 3: Hermitian matrix model. Tensor models and Permutation centralizer al- gebras. Using permutation equivalences to count matrix/tensor invariants and compute correlators. Relations to covering spaces.)

01.12.2017 (Friday)

Graduate Mini-course: Holographic combinatorics : 2d Yang Mills theory to tensor models via AdS/CFT

Triangular Seminar Sanjaye Ramgoolam (QMUL)

at:
11:00 QMW
room GO Jones 610
abstract:

These lectures will be focused on aspects of combinatorics relevant to gauge-string duality (holography). The physical theories we will discuss include two dimensional Yang Mills theory, four-dimensional N=4 super Yang Mills theory with U(N) gauge group, Matrix and tensor models. The key mathematical concepts include : Schur Weyl-duality, permutation equivalence classes and associated discrete Fourier transforms as an approach to counting problems and, branched covers and Hurwitz spaces. Schur-Weyl duality is a powerful relation between representations of U(N) and representations of symmetric groups. Representation theory of symmetric groups offers a method to define nice bases for functions on equivalence classes of permutations. These bases are useful in counting gauge invariant functions of matrices or tensors, as well as computing their correlators in physical theories. In AdS/CFT these bases have proved useful in identifying local operators in gauge-theory dual to giant gravitons in AdS. In the simplest cases of gauge-string duality, the known mathematics of branched covers and Hurwitz spaces provide the mechanism for the holographic correspondence between gauge invariants and stringy geometry. (Lecture 2: Local gauge invariant operators and Hilbert space of CFTs. Young diagrams and Brane geometries. Half-BPS and quarter-BPS. Counting, construction and correlators in group theoretic combinatorics.)