Tue, 04 Nov 2014
15:45
L4

Cobordisms between tangles

Akram Alishahi
(Bonn)
Abstract

 In a previous work, we introduced a refinement of Juhasz’s sutured Floer homology, and constructed a minus theory for sutured manifolds, called sutured Floer chain complex. In this talk, we introduce a new description of sutured manifolds as “tangles” and describe a notion of cobordism between them. Using this construction, we define a cobordism map between the corresponding sutured Floer chain complexes. We also discuss some possible applications. This is a joint work with Eaman Eftekhary.

Tue, 28 Oct 2014

15:45 - 16:45
L4

Infinitely many monotone Lagrangian Tori in CP^2

Renato Vianna
(Cambridge)
Abstract
In previous work, we constructed an exotic monotone Lagrangian torus in CP2 (not Hamiltonian isotopic to the known Clifford and Chekanov tori) using techniques motivated by mirror symmetry. We named it T(1,4,25) because, when following a degeneration of CP2 to the weighted projective space CP(1,4,25), it degenerates to the central fibre of the moment map for the standard torus action on CP(1,4,25). Related to each degeneration from CP2 to CP(a2,b2,c2), for (a,b,c) a Markov triple -- a2+b2+c2=3abc -- there is a monotone Lagrangian torus, which we call T(a2,b2,c2).  We employ techniques from symplectic field theory to prove that no two of them are Hamiltonian isotopic to each other.
Tue, 11 Nov 2014

12:00 - 13:00
L5

SYM amplitudes from BRST symmetry

Oliver Schlotterer
(AEI Golm)
Abstract
This talk describes a method to compute supersymmetric tree amplitudes and loop integrands in ten-dimensional super Yang-Mills theory. It relies on the constructive interplay between their cubic graph organization and BRST invariance of the underlying pure spinor superspace description. After a general introduction to this kind of superspace, we discuss a canonical set of multiparticle building blocks which represent tree level subdiagrams and are guided by their BRST transformation. These building blocks are shown to yield a compact solution for tree level amplitudes, and the applicability of the BRST approach to loop integrands is exemplified through recent examples at one-loop.
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