Seminars of interest to string theorists in Oxford this week
- On Monday 2nd December at noon in L5, the String seminar
Nima Arkani-Hamed (IAS, Princeton)
- On Monday 2nd December at 2:10 in L5, the Geometry and Analysis seminar
Yanki Lekili (KCL)
Floer cohomology and Platonic solidsAbstract: We consider Fano threefolds on which SL(2,C) acts with a dense open orbit. This is a finite list of threefolds whose classification follows from the classical work of Mukai-Umemura and Nakano. Inside these threefolds, there sits a Lagrangian space form given as an orbit of SU(2). We prove this Lagrangian is non-displaceable by Hamiltonian isotopies via computing its Floer cohomology over a field of non-zero characteristic. The computation depends on certain counts of holomorphic disks with boundary on the Lagrangian, which we explicitly identify. This is joint work in progress with Jonny Evans.
- On Tuesday 3rd December at noon in L5, the Relativity seminar
- On Tuesday 3rd December two seminars in the Holography series
at 2:00 in the BIPAC Seminar Room of DWB:
Rob Myers (Perimeter Institute)
Quantum Quenches and Holography
at 5:00 in the Seminar Room (Rm 501) of DWB:
Hansjörg Zeller (Max Planck Insitute, Munich)
Transport Properties of Holographic P-Wave SuperfluidsAbstract: Due to the spacetime anisotropy of the holographic p-wave superfluid, the tensorial structure of the transport coefficients is non-trivial in contrast to the isotropic case. In particular, there is an additional shear mode which leads to a non-universal value of the shear viscosity even in an Einstein gravity setup. Furthermore, we find two optical conductivities with very different low frequency behaviour, one of which resembles a broad Drude peak. In this talk, I will present these phenomena and some other transport properties of this system.
- On Tuesday 3rd December at 3:45 in L4, a seminar in the Algebraic and Symplectic Geometry series
Ian Grojnowski (Cambridge)
- On Wednesday 4th December at noon in L5, the string theory bag lunch
Paul Richmond (Oxford)
Localisation in supersymmetric gauge theories 1Background reading: arXiv:0909.4559 and arXiv1104.0783.
- On Thursday 5th December at 1:00 in the Dalitz Institute of DWB, the Particle Theory Journal Club
Stephen Angus (Oxford)
- On Thursday 5th December at 4:15 in the Dennis Sciama Lecture Theatre of DWB, the Particle and Fields seminar
Subodh Patil (CERN)
Heavy fields, decoupling and the effective theory of inflationAbstract: We compute the low energy effective field theory (EFT) expansion for single-field inflationary models that descend from a parent theory containing multiple other scalar fields. By assuming that all other degrees of freedom in the parent theory are sufficiently massive relative to the inflaton, it is possible to derive an EFT valid to arbitrary order in perturbations, provided certain generalized adiabaticity conditions are respected. These conditions permit a consistent low energy EFT description even when the inflaton deviates off its adiabatic minimum along its slowly rolling trajectory. By generalizing the formalism that identifies the adiabatic mode with the Goldstone boson of this spontaneously broken time translational symmetry prior to the integration of the heavy fields, we show that this invariance of the parent theory dictates the entire non-perturbative structure of the descendent EFT. The couplings of this theory can be written entirely in terms of the reduced speed of sound of adiabatic perturbations. The resulting operator expansion is distinguishable from that of other scenarios, such as standard single inflation or DBI inflation. In particular, we re-derive how certain operators can become transiently strongly coupled along the inflaton trajectory, consistent with slow-roll and the validity of the EFT expansion, imprinting features in the primordial power spectrum, and we deduce the relevant cubic operators that imply distinct signatures in the primordial bispectrum which may soon be constrained by observations.
- On Friday 6th December at 2:00 in the Dennis Sciama Lecture Theatre of DWB, the Theoretical Physics Colloquium
No Seminar (even week)
- On Friday 6th December at 4:00 in L1, a special Number Theory seminar
Ken Ono (Emory University)
Special numbers and special functions related to Ramanujan's mock modular formsAbstract: This lecture will cover two recent works on the mock modular forms of Ramanujan: I. Solution of Ramanujan's original conjectures about these functions (Joint work with Folsom and Rhoades). II. A new theorem that mock modular forms are "generating functions" for central L-values and derivatives of quadratic twist L-functions.(Joint work with Alfes, Griffin, Rolen).
- On Friday 6th December at 4:15 in the Martin Wood Lecture Theatre of the Clarendon Laboratory, the Department of Physics Colloquium
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