This Week

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

On Monday at 12:45 in L3, a seminar in the String Theory series:
No Seminar
On Tuesday at 11:30 in Simpkins Lee Room, Beecroft Building, a seminar in the Cosmology series:
Boris Bolliet (University of Manchester)
Cosmological constraints from the thermal Sunyaev Zeldovich power spectrum and cluster counts
On Tuesday at 12:00 in L4, a seminar in the Quantum Field Theory series:
Joseph Conlon (Oxford)
The Swampland, Holography and the Large Volume Scenario
Further information: String compactifications are essential for connecting string theory to low energy particle physics and cosmology. Moduli stabilisation gives rise to effective Lagrangians that capture the low-energy degrees of freedom. Much recent interest has been on swampland consistency conditions on such effective field theories - which low energy Lagrangians can arise from quantum gravity? Furthermore, given that moduli stabilisation scenarios often exist in AdS space, we can also ask: what do swampland conditions mean in the context of AdS/CFT? I describe work on developing a holographic understanding of moduli stabilisation and swampland consistency conditions. I focus in particular on the Large Volume Scenario, which is especially appealing from a holographic perspective as in the large volume limit all its interactions can be expressed solely in terms of the AdS radius, with no free dimensionless parameters.  
On Tuesday at 15:30 in L4, a seminar in the Algebraic Geometry series:
Dominic Bunnett (FU Berlin)
Moduli of hypersurfaces in weighted projective space
Further information: The moduli space of smooth hypersurfaces in projective space was constructed by Mumford in the 60’s using his newly developed classical (a.k.a. reductive) Geometric Invariant Theory.  I wish to generalise this construction to hypersurfaces in weighted projective space (or more generally orbifold toric varieties). The automorphism group of a toric variety is in general non-reductive and I will use new results in non-reductive GIT, developed by F. Kirwan et al., to construct a moduli space of quasismooth hypersurfaces in certain weighted projective spaces. I will give geometric characterisations of notions of stability arising from non-reductive GIT.
On Tuesday at 16:00 in C5, a seminar in the Twistor Workshop series:
Dhritiman Nandan (Southampton)
Celestial Amplitudes: conformal partial waves and soft theorems
Further information: Massless scattering amplitudes in four-dimensional Minkowski spacetime can be Mellin transformed to correlation functions on the celestial sphere at null infinity called celestial amplitudes. We study various properties of massless four-point scalar and gluon celestial amplitudes such as conformal partial wave decomposition, crossing relations and optical theorem. As a byproduct, we derive the analog of the single and double soft limits for all gluon celestial amplitudes.
On Thursday at 12:45 in L6, a seminar in the Strings Junior series:
Diego Berdeja Suarez
Seiberg-Witten theory
On Thursday at 13:00 in Simpkins Lee Seminar Room, a seminar in the Dalitz Seminar in Fundamental Physics series:
Markus Ebert (MIT)
Power corrections for fixed-order subtractions
On Thursday at 16:00 in L6, a seminar in the Number Theory series:
Michalis Neururer (TU Darmstadt)
Fourier expansions at cusps and the Manin constant of elliptic curves
Further information: I will discuss the arithmetic significance of Fourier expansions of modular forms at cusps. I will talk about joint work with F. Brunault, where we determine the number field generated by Fourier coefficients of newforms at a cusp. Then I will discuss joint work with A. Saha and K. Česnavičius where we find denominator bounds for Fourier expansions at cusps and apply these bounds to a conjecture on the Manin constants of elliptic curves.
On Thursday at 16:15 in Simpkins Lee Room, Beecroft Building, a seminar in the Theoretical Particle Physics series:
Maria Ubiali (DAMTP Cambridge)
Can New Physics hide in the proton PDFs?
On Friday at 15:30 in Martin Wood Lecture Theatre, a seminar in the Colloquia Series Seminars series:
Professor Thirumalai Venkatesan (National University of Singapore)
Bridging the divide - academic entrepreneurship