String Theory Seminar
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Mon, 26/04/2010 12:00 |
Yang-Hui He (Oxford) |
String Theory Seminar  |
L3 |
| We investigate certain arithmetic properties of field theories. In particular, we study the vacuum structure of supersymmetric gauge theories as algebraic varieties over number fields of finite characteristic. Parallel to the Plethystic Programme of counting the spectrum of operators from the complex geometry, we investigate the Hasse-Weil zeta functions and the associated Dirichlet expansions. We find curious dualities wherein the geometrical properties and asymptotic behaviour of one gauge theory is governed by the number theoretic nature of another. | |||
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Fri, 30/04/2010 12:00 |
Burt Ovrut (University of Pennsylvania) |
String Theory Seminar |
L3 |
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Mon, 10/05/2010 12:00 |
Masahito Yamazaki (Tokyo) |
String Theory Seminar |
L3 |
| I will describe the wall crossing phenomena for (generalized) Donaldson-Thomas invariants (also known as BPS invariants) from a physicist's perspective; the topics include crystal melting and its thermodynamic limit, M-theory derivation of wall crossing, and open wall crossing. | |||
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Mon, 17/05/2010 12:00 |
James Gray (Oxford) |
String Theory Seminar |
L3 |
| I will discuss various aspects of Calabi-Yau compactifications appropriate for use in models of string phenomenology. Topics covered will include transitions between and deformations of bundles as well as consequences of stability walls for phenomenology. | |||
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Mon, 24/05/2010 12:00 |
Djordje Minic (VirginiaTech) |
String Theory Seminar |
L3 |
| Recent theoretical advances in string theory relate in an unexpected way the physics of gravity in certain D dimensional space-times with the dynamics of quantum field theories living on the associated (D-1) dimensional space-time boundary. This unsuspected relationship offers a remarkable new tool for dealing with some outstanding problems in condensed matter physics. In the first part of the talk I aim to explain both the intuitive and technical underpinnings of these new developments. In the second half of the talk I will present some recent results on aging in systems far from equilibrium and also some new avenues for research in condensed matter physics which involve the interplay of gauge fields, membranes and many-body systems. In particular this last work opens up an exciting possibility for fundamentally new states of condensed matter. | |||
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Fri, 28/05/2010 16:00 |
Per Berglund (CERN/New Hampshire) |
String Theory Seminar |
L1 |
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Mon, 07/06/2010 12:00 |
Dario Martelli (Kings College London) |
String Theory Seminar |
L3 |
| We study a gravity solution corresponding to fivebranes wrapped on the S^2 of the resolved conifold. By changing a parameter the solution continuously interpolates between the deformed conifold with flux and the resolved conifold with branes. Therefore, it displays a geometric transition, purely in the supergravity context. The solution is a simple example of torsional geometry and may be thought of as a non-Kahler analog of the conifold. By U-duality transformations we can add D3 brane charge and recover the solution in the form originally derived by Butti et al. This describes the baryonic branch of the Klebanov-Strassler theory. Far along the baryonic branch the field theory gives rise to a fuzzy two-sphere. This corresponds to the D5 branes wrapping the two-sphere of the resolved conifold in the gravity solution. | |||
