Tue, 12 Feb 2013

14:30 - 15:30
L3

From monotone arithmetic progressions to bounded additive complexity in infinite words

Veselin Jungic
(Simon Fraser University)
Abstract

I will describe how a search for the answer to an old question about the existence of monotone arithmetic progressions in permutations of positive integers led to the study of infinite words with bounded additive complexity. The additive complexity of a word on a finite subset of integers is defined as the function that, for a positive integer $n$, counts the maximum number of factors of length $n$, no two of which have the same sum.

Mon, 18 Feb 2013

12:00 - 13:00
L3

A magic square from Yang-Mills squared

Mike Duff
(Imperial College)
Abstract
I will give a division algebra R,C,H,O description of D = 3 Yang-Mills with N = 1,2,4,8 and hence, by tensoring left and right multiplets, a magic square RR, CR, CC, HR, HC, HH, OR, OC, OH, OO description of D = 3 supergravity with N = 2, 3, 4, 5, 6, 8, 9, 10, 12, 16.
Mon, 11 Feb 2013

12:00 - 13:00
L3

On sequestering and decoupling in stabilized string models

David Marsh
(Oxford)
Abstract
I will describe recent efforts to understand the mediation of supersymmetry breaking in stabilized compactifications of type IIB string theory. By geometrically separating the visible sector from the supersymmetry breaking effects one may hope to achieve sequestered supersymmetry breaking and much ameliorated constraints from bounds on flavor changing neutral currents. However, in this talk I will discuss how non-perturbative superpotential cross-couplings between the visible sector and the Kähler moduli may spoil sequestering and introduce a sensitivity to the global details of the compactification. As a simple example, I will describe the structure of these `de-sequestering’ operators for a class of visible sectors realized by D-branes probing an orbifold singularity, and I will discuss their importance in the KKLT and LVS moduli stabilization scenarios.
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