Global string models with chiral matter and moduli stabilisation
Abstract
I will discuss the implementation of explicit stabilisation of all closed string moduli in fluxed type IIB Calabi-Yau compactifications with chiral matter. Using toric geometry we construct Calabi-Yau manifolds with del Pezzo singularities. D-branes located at such singularities can support the Standard Model gauge group and matter content. We consider Calabi-Yau manifolds with a discrete symmetry that reduces the effective number of complex structure moduli, which allows us to calculate the corresponding periods and find explicit flux vacua. We compute the values of the flux superpotential and the string coupling at these vacua. Starting from these explicit complex structure solutions, we obtain AdS and dS minima where the Kaehler moduli are stabilised by a mixture of D-terms, non-perturbative and perturbative alpha'-corrections as in the LARGE Volume Scenario.
Calabi-Yau Fourfolds, F-theory and Fluxes
Abstract
I will discuss several recent developments regarding the construction of fluxes for F-theory on Calabi-Yau fourfolds. Of particular importance to the effective physics is the structure of the middle (co)homology groups, on which new results are presented. Fluxes dynamically drive the fourfold to Noether-Lefschetz loci in moduli space. While the structure of such loci is generally unknown for Calabi-Yau fourfolds, this problem can be answered in terms of arithmetic for K3 x K3 and a classification is possible.
Oxford Mathematics Professor Mason Porter and former postdoctoral student Sang Hoon Lee, now of Sungkyunkwan University in Korea, have found a new way of analysing population mix. In the past patterns in human movement have been studied using traffic data, mobile phone records, and even dollar bill circulation.
Family Drop-In Art Workshops
Abstract
Struggling for ideas at the weekends? Learn how to draw with colour and discover the creation of colour from our natural environment. Have a go at making your own natural paint colours. Create your own mini planet inspired by alchemy and the Radcliffe Observatory. Paint making demonstrations throughout the day with artist Nabil Al. All materials provided. Suitable for all ages from 6 to 60. Invite your friends.
17:00
Big Data's Big Deal
Abstract
Viktor Mayer-Schönberger is Professor of Internet Governance and Regulation at the University of Oxford's Internet Institute. He is also a faculty affiliate of Harvard's Belfer Center for Science and International Affairs. Together with Kenneth Cukier he is the co-author of the international bestseller Big Data.
14:00
Pandora's Promise
Abstract
Grothendieck Duality through Modern Methods
Abstract
12:00
On the symmetries of “Yang-Mills squared”
Abstract
A recurring theme in attempts to understand the quantum theory of gravity is the idea of "Gravity as the square of Yang-Mills". In recent years this idea has been met with renewed energy, principally driven by a string of discoveries uncovering intriguing and powerful identities relating gravity and gauge scattering amplitudes. In an effort to develop this program further, we explore the relationship between both the global and local symmetries of (super)gravity and those of (super) Yang-Mills theories squared. In the context of global symmetries we begin by giving a unified description of D=3 super-Yang-Mills theory with N=1, 2, 4, 8 supersymmeties in terms of the four division algebras: reals, complex, quaternions and octonions. On taking the product of these multiplets we obtain a set of D=3 supergravity theories with global symmetries (U-dualities) belonging to the Freudenthal magic square: “division algebras squared” = “Yang-Mills squared”! By generalising to D=3,4,6,10 we uncover a magic pyramid of Lie algebras. We then turn our attention to local symmetries. Regarding gravity as the convolution of left and right Yang-Mills theories together with a spectator scalar field in the bi-adjoint representation, we derive in linearised approximation the gravitational symmetries of general covariance, p-form gauge invariance, local Lorentz invariance and local supersymmetry from the flat space Yang-Mills symmetries of local gauge invariance and global super-Poincaré. As a concrete example we focus on the new-minimal (12+12, N=1) off-shell version four-dimensional supergravity obtained by tensoring the off-shell (super) Yang-Mills multiplets (4+4, N =1) and (3+0, N =0).