## 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)

### 13.09.2018 (Thursday)

#### Central charge of self-dual strings from holography

Regular Seminar Ronnie Rodgers (Southampton U.)

 at: 14:00 QMWroom G O Jones 610 abstract: M-theory is a candidate for a theory of quantum gravity. Its fundamental objects are called M2-branes and M5-branes. The low-energy theory describing coincident M5-branes is poorly understood in many respects, with holography providing one of the most useful tools to further that understanding. It is known that the theory should possess solitonic solutions called "self-dual strings". An important quantity characterising these strings is their central charge, which among other things counts the massless degrees of freedom on the string. I will describe configurations of M-branes dual to the insertion of infinite tension self-dual strings into the M5-brane theory, and how calculation of holographic entanglement entropy in such set-ups yields the central charge of the self-dual string.

### 23.07.2018 (Monday)

#### Einstein Double Field Equations

Regular Seminar Jeong-Hyuck Park (Sogang University)

 at: 15:30 QMWroom 410 abstract: String theory predicts its own gravity rather than GR. In General Relativity the metric is the only geometric and gravitational field, whereas in string theory the closed-string massless sector comprises a skew-symmetric B-field and the string dilaton in addition to the metric. Furthermore, these three fields transform into each other under T-duality. This hints at a natural augmentation of GR: upon treating the whole closed string massless sector as stringy graviton fields, Double Field Theory may evolve into `Stringy Gravity'. Equipped with an O(D,D) covariant differential geometry beyond Riemann, we spell out the definitions of the stringy Einstein curvature tensor and the stringy Energy-Momentum tensor. Equating them, all the equations of motion of the closed string massless sector are unified into a single expression which we dub the Einstein Double Field Equations.

### 21.06.2018 (Thursday)

#### Submatrix deconfinement and small black holes in AdS

Regular Seminar David Berenstein (UC Santa Barbara)

 at: 14:00 QMWroom G O Jones 610 abstract:

### 07.06.2018 (Thursday)

#### Viscoelastic holography: from fluids to solids

Regular Seminar Matteo Baggioli (Crete U.)

 at: 14:00 QMWroom G O Jones 610 abstract: A review of the recent progress regarding the holograhic duals for viscoelastic and solid materials. After introducing a simple bottom-up model able of realizing such a setup the following physical properties will be discussed: i) the linear elastic features ii) viscoelasticity ii) the nature of phonons and pinning iii) the non linear elastic properties iiii) the convergence properties of the asymptotic expansion.

### 31.05.2018 (Thursday)

#### Perfect probabilistic storing and retrieving of unitary channels

Regular Seminar Michal Sedlak (Slovak Academy of Sciences)

 at: 14:00 QMWroom G O Jones 610 abstract: Any sequence of quantum gates on a set of qubits defines a multipartite unitary transformation. These sequences may correspond to some parts of a quantum computation or they may be used to encode classical/quantum information (e.g. in private quantum channels). If we have only limited access to such a unitary transformation, we may want to store it into a quantum memory and later perfectly retrieve it. Thus, once we cannot use the unitary transformation directly anymore, we could still apply it to any state with the help of the footprint kept in the quantum memory. This can be useful for speeding up some calculations or as an attack for process based quantum key distribution protocol or a communication scheme. We require the storing and retrieving protocol to perfectly reconstruct the unitary transformation, which implies non unit probability of success. We derive optimal probability of success for a d-dimensional unitary transformation used N-times. The optimal probability of success has a very simple form N/(N-1+d^2). This result implies that reliable storing of d^2 parameters of the unknown unitary transformation requires roughly d^2 uses of the transformation.

### 30.05.2018 (Wednesday)

#### Exotic Rational CFT and the Modular Bootstrap

Regular Seminar Sunil Mukhi (IISER, Pune)

 at: 14:00 QMWroom G O Jones 610 abstract: I will summarise old and recent developments on the classification and solution of Rational Conformal Field Theories in 2 dimensions using the method of Modular Differential Equations. Novel and exotic theories are found with small numbers of characters and simple fusion rules, one of these being the Baby Monster CFT. Correlation functions for many of these theories can be computed using crossing-symmetric differential equations.

### 24.05.2018 (Thursday)

#### Positivity Constraints in Effective Field Theories

Regular Seminar Andrew Tolley (Imperial College London)

 at: 14:00 QMWroom 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 QMWroom 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 QMWroom 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 QMWroom 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 QMWroom 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 QMWroom 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 QMWroom 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 QMWroom 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 QMWroom 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 QMWroom Peoples Palace PP01 abstract:

### 22.02.2018 (Thursday)

#### Knot Invariants and M theory

Regular Seminar Radu Tatar (Liverpool U.)

 at: 14:00 QMWroom 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 QMWroom 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 QMWroom 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 QMWroom 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.