Triangle Seminars
Monday, 28 Jan 2008
Counting curves in Calabi-Yau 3-folds
Richard Thomas
(Imperial College)
Abstract:
These will be introductory lectures surveying GW, MNOP and GV invariants – all different ways of counting curves.
For a string theorist this involves seeing the curve as, respectively, the world sheet of a string, a D-brane, or a BPS thingummy.
I will describe a 4th way via stable pairs, which in effect means counting D-branes (or stable objects of the derived category, to mathematicians) after a change of stability condition.
These will be introductory lectures surveying GW, MNOP and GV invariants – all different ways of counting curves.
For a string theorist this involves seeing the curve as, respectively, the world sheet of a string, a D-brane, or a BPS thingummy.
I will describe a 4th way via stable pairs, which in effect means counting D-branes (or stable objects of the derived category, to mathematicians) after a change of stability condition.
Posted by: IC
Tuesday, 29 Jan 2008
RMT, QCD and a mapping theorem through superbosonisation
Francesco Basile
(Brunel/Pisa)
Rhombus tilings in representation theory
Joseph Chuang
(City University London)
Abstract:
I'll introduce a combinatorial problem on tilings of the plane by rhombi and explain how the solution is related to the representation theory of groups.
I'll introduce a combinatorial problem on tilings of the plane by rhombi and explain how the solution is related to the representation theory of groups.
Posted by: KCL
Wednesday, 30 Jan 2008
Dyon Death Eaters
📍 London
Sunil Mukhi
(Tata Institute)
Abstract:
I will describe and analyse general two-body decays of primitive and non-primitive 1/4-BPS dyons in four-dimensional type IIB string compactifications. For half-BPS decays, a relation is found between walls of marginal stability and the mathematics of Farey sequences and Ford circles. The relationship of marginal decay to the breakup of multi-centred dyons will also be discussed.
I will describe and analyse general two-body decays of primitive and non-primitive 1/4-BPS dyons in four-dimensional type IIB string compactifications. For half-BPS decays, a relation is found between walls of marginal stability and the mathematics of Farey sequences and Ford circles. The relationship of marginal decay to the breakup of multi-centred dyons will also be discussed.
Posted by: IC
Instanton effects from open strings and D-branes
📍 London
Alberto Lerda
(Piemonte Orientale U., Alessandria)
Abstract:
We discuss how non-perturbative instanton effects in supersymmetric gauge theories can be described using open strings and D-branes. We analyse ordinary gauge instantons as well as novel 'exhotic instanton' configurations of purely stringy nature, and discuss their applications and effets in the low-energy effective theory.
We discuss how non-perturbative instanton effects in supersymmetric gauge theories can be described using open strings and D-branes. We analyse ordinary gauge instantons as well as novel 'exhotic instanton' configurations of purely stringy nature, and discuss their applications and effets in the low-energy effective theory.
Posted by: KCL