Found 15 result(s)
Regular Seminar Jose Miguel FigueroaO'Farrill (Edinburgh)
at: 13:15 room G01 Norfolk Building  abstract: I will report on joint work with Andrea Santi outlining an algebraic reformulation of the classification problem of elevendimensional supergravity backgrounds. The basic object of study is the Killing superalgebra of the background, whose algebraic structure has recently been elucidated. If time permits I will also comment on work also involving Paul de Medeiros applying these techniques to the construction of rigidly supersymmetric theories in curved spaces. 
Regular Seminar John Joseph Carrasco (CEA)
at: 14:00 room G.O. Jones 610  abstract: One can easily be frustrated by the tremendous redundancy in possible physical description. By this I mean the freedom to choose gauge, make field redefinitions, add any amount of auxiliary spectator matter, and the such. Happily we can exploit such freedom to encourage the emergence of a new duality in gauge theories. The existence of a duality between color and kinematics exposes a hidden local doublecopy structure inherent to prediction in many theories. This structure weaves its way between theories both formal and phenomenological, from QCD to Gravity, from Chiral Perturbation Theory to BornInfeld and VolkovAkulov, and from open to closed superstring theories. The duality is sharpest at the level of the perturbative Smatrix — so I will focus my talk there, although I will also mention some recent provocative work beyond scattering. I will mainly discuss progress and challenges to generically achieving colordual kinematic representations at the multiloop level. I present a path forward that introduces, at least temporarily, a redundancy of description that we can exploit to map a set of functional relations to linear ones. I will talk about this approach in terms of a geometric picture involving the graph of local graphs, discussing tradeoffs and applicability to longstanding problems. 
Regular Seminar Jose FernandezMelgarejo (Harvard)
at: 13:30 room H503  abstract: We study the general formulation of gauged supergravity in seven dimensions with sixteen supercharges keeping duality covariance by means of the embedding tensor formalism. We first classify all inequivalent duality orbits of consistent deformations. Secondly, we analyse the complete set of critical points in a systematic way. Interestingly, we find the first examples of stable de Sitter solutions within a theory with such a large amount of supersymmetry. 
Regular Seminar Joseph Conlon (Oxford U., Theor. Phys.)
at: 13:30 room H503  abstract:

Regular Seminar Joseph Ben Geloun (AEI Golm)
at: 14:00 room G.O. Jones 610  abstract: A review will be provided on the renormalization program for the socalled Tensor Models for Quantum Gravity. These are non local field theories extending both the matrix models, a successful framework in statistical mechanics applied to 2D physics, and the GrosseWulkenhaar model in the matrix basis arising in Noncommuting Neometry. We will emphasize the Multiscale renormalization but also report recent results on the Functional Renormalization Group Approach for these class of models. 
Informal Seminar Anosh Joseph (DESY)
at: 15:00 room H503  abstract: Certain classes of supersymmetric YangMills (SYM) theories including the well known N=4 SYM, that takes part in the AdS/CFT correspondence, can be formulated on a Euclidean spacetime lattice using the techniques of exact lattice supersymmetry. In this talk I will provide the constructions of such theories and describe how great ideas such as topological field theories, DiracKahler fermions, geometric discretization all come together to create lattice SYM theories that are exactsupersymmetric, gaugeinvariant, local and doublerfree on the lattice. Then I move on to discuss the recent lattice constructions of specific classes SYM theories in two dimensions, with matter in various representations. 
Regular Seminar Jose Edelstein (University of Santiago de Compostela)
at: 14:00 room Lecture Theatre  abstract: Lovelock theory is the natural extension of general relativity to higher dimensions. It can be also thought of as a toy model for ghostfree higher curvature gravity. It admits a family of AdS vacua, most (but not all) of them supporting black holes, that display interesting features such as a generalized variant of the HawkingPage phase transition. This provides an appealing arena to explore different holographic aspects in the context of the AdS/CFT correspondence which I will discuss in this talk. 
Regular Seminar Joseph Conlon (Oxford)
at: 13:15 room S4.23  abstract: TransPlanckian inflationary excursions are very interesting because they are sensitive to Plancksuppressed operators and can generate observable tensor modes. I review one proposed model generating a transPlanckian excursion and argue that consideration of antibrane backreaction renders the assumptions entering the model inconsistent. 
Regular Seminar Jose FigueroaO'Farrill (Edinburgh)
at: 13:30 room H503  abstract: We've known since childhood that symmetry can be a very powerful tool in solving partial differential equations. With a little symmetry, one can reduce the number of independent variables, whereas with some more symmetry one can usually separate variables and reduce the problem to solving ordinary differential equations. Given enough symmetry, though, partial differential equations become algebraic. A large body of current research in our field requires finding solutions to the (super)gravity field equations and in this talk I will motivate the search for homogeneous supergravity backgrounds and mention some recent results in this area. 
Regular Seminar Joseph Conlon (Oxford)
at: 13:45 room 410A  abstract: Local string models are those where Standard Model degrees of freedom arise on a small region inside a large bulk volume. I study threshold effects on gauge coupling running for such models. The KaplunovskyLouis formula for locally supersymmetric gauge theories predicts the unification scale should be the bulk winding mode scale, parametrically large than the string scale where divergences are naively cut off. Analysis of explicit string models on orbifold/orientifold geometries confirms this. The winding mode scale arises from the presence of tadpoles uncancelled in the local model. I briefly discuss phenomenological applications to supersymmetry breaking and gauge coupling unification. 
Triangular Seminar Jose FigueroaO'Farrill (University of Edinburgh)
at: 16:00 room LG1  abstract: I will discuss several constructions of superalgebras associated to the Killing spinors of a supergravity background, with special emphasis on the ten and elevendimensional supergravities. 
Regular Seminar Joseph Chuang (City University London)
at: 17:00 room C322  abstract: I'll introduce a combinatorial problem on tilings of the plane by rhombi and explain how the solution is related to the representation theory of groups. 
Triangular Seminar Jose FigueroaO'Farrill (Edinburgh)
at: 15:00 room 410  abstract:

Triangular Seminar Jose Barbon (Madrid)
at: 15:00 room Lecture Theatre 3, Blackett Laboratory  abstract: I review general features of AdS/CFT models with dynamical quarks, with particular emphasis on chiral dynamics. I also show how these models incorporate the nontrivial interplay between the solution of the U(1) problem in QCD and the 1/N expansion. 
Regular Seminar Jose' FigueroaO' Farrill (Edinburgh)
at: 14:00 room 112  abstract:
