# Next Week

Here is a selection of seminars that might be of interest to string theorists in Oxford:

On Monday at 14:00 in Dennis Sciama Lecture Theatre, a seminar in
the Astrophysics Colloquia series:

No Seminar (Bank Holiday)

On Monday at 14:15 in L4, a seminar in
the Geometry and Analysis series:

Philip Boalch (Orsay)

Nonabelian Hodge spaces and nonlinear representation theory

*The theory of connections on curves and Hitchin systems is something like a “global theory of Lie groups”, where one works over a Riemann surface rather than just at a point. We’ll describe how one can take this analogy a few steps further by attempting to make precise the class of rich geometric objects that appear in this story (including the non-compact case), and discuss their classification, outlining a theory of “Dynkin diagrams” as a step towards classifying some examples of such objects.*

**Further information:**
On Tuesday at 11:30 in Bipac Seminar Room, DWB, a seminar in
the Cosmology series:

Andrew Pontzen (UCL)

Insights into non-linear structure growth from inverted initial conditions

On Tuesday at 12:00 in L4, a seminar in
the Relativity series:

Paul Townsend (DAMTP Cambridge)

Supertwistors: the massless, the massive, and the AdS

*Some recent applications of supertwistors to superparticle mechanics will be reviewed. First: Supertwistors allow a simple quantization of the N-extended 4D massless superparticle, and peculiarities of massless 4D supermultiplets can then be explained by considering the quantum fate of a classical ``worldline CPT'' symmetry. For N=1 there is a global CPT anomaly, which explains why there is no CPT self-conjugate supermultiplet. For N=2 there is no anomaly but a Kramers degeneracy explains the doubling of states in the CPT self-conjugate hypermultiplet. Second: the bi-supertwistor formulation of the N-extended massive superparticle in 3D, 4D and 6D makes manifest a ``hidden’’ 2N-extended supersymmetry. It also has a simple expression in terms of hermitian 2x2 matrices over the associative division algebras R,C,H. Third: omission of the mass-shell constraint in this 3D,4D,6D bi-supertwistor action yields, as suggested by holography, the action for a supergraviton in 4D,5D,7D AdS. Application to the near horizon AdSxS geometries of the M2,D3 and M5 brane confirms that the graviton supermultiplet has 128+128 polarisation states.*

**Further information:**
On Tuesday at 14:00 in DWB Fisher Room, a seminar in
the Holography series:

Marika Taylor (U. Southampton)

AdS_3, dilaton gravity and SYK

On Tuesday at 15:45 in L4, a seminar in
the Algebraic and Symplectic Geometry series:

Jack Smith (Cambridge)

Symmetries in monotone Lagrangian Floer theory

*Lagrangian Floer cohomology groups are extremely hard compute in most situations. In this talk I’ll describe two ways to extract information about the self-Floer cohomology of a monotone Lagrangian possessing certain kinds of symmetry, based on the closed-open string map and the Oh spectral sequence. The focus will be on a particular family of examples, where the techniques can be combined to deduce some unusual properties.*

**Further information:**
On Thursday at 12:45 in L6, a seminar in
the Strings Junior series:

Pietro Benetti Genolini

K-theory

On Thursday at 13:00 in Dalitz Institute, a seminar in
the Dalitz Seminar in Fundamental Physics series:

Luigi Delle Rose (RAL & Southampton)

Wilsonian Dark Matter in String Derived Z′ Model

On Thursday at 16:00 in L6, a seminar in
the Number Theory series:

Rebecca Bellovin (Imperial College, London)

TBA