Triangle Seminars
Tuesday, 20 Mar 2007
Informal Lecture on the Geometric Langlands Correspondence (1 of 2)
📍 London
Joerg Teschner
(DESY Hamburg)
Abstract:
(the second lecture will be on Wednesday morning)
(the second lecture will be on Wednesday morning)
Posted by: KCL
Wednesday, 21 Mar 2007
Integrability, Transcendentality and Crossing
Burkhard Eden
(Utrecht University)
Abstract:
We analyze the all-loop Bethe ansatz for the sl(2) twist
operator sector of the N=4 gauge theory in the limit
of large spacetime spin at large but finite twist, and find a
novel all-loop scaling function. This function obeys the
Kotikov-Lipatov transcendentality principle and does not depend
on the twist.
We discuss possible phase factors for the
S-matrix, leading to modifications at four-loop order and beyond.
While these result in a four-loop breakdown of perturbative BMN-scaling,
transcendentality may be preserved in the universal scaling function.
One particularly natural dressing phase, unique up to one
constant, modifies the overall contribution of all terms
in the scaling function that contain odd zeta functions.
Excitingly, we present evidence that this choice is non-perturbatively
related to a recently conjectured crossing-symmetric phase factor
for perturbative string theory on AdS(5)xS(5) once the constant is
fixed to a particular value.
Our proposal, if true, might therefore resolve the long-standing
AdS/CFT discrepancies between gauge and string theory.
We analyze the all-loop Bethe ansatz for the sl(2) twist
operator sector of the N=4 gauge theory in the limit
of large spacetime spin at large but finite twist, and find a
novel all-loop scaling function. This function obeys the
Kotikov-Lipatov transcendentality principle and does not depend
on the twist.
We discuss possible phase factors for the
S-matrix, leading to modifications at four-loop order and beyond.
While these result in a four-loop breakdown of perturbative BMN-scaling,
transcendentality may be preserved in the universal scaling function.
One particularly natural dressing phase, unique up to one
constant, modifies the overall contribution of all terms
in the scaling function that contain odd zeta functions.
Excitingly, we present evidence that this choice is non-perturbatively
related to a recently conjectured crossing-symmetric phase factor
for perturbative string theory on AdS(5)xS(5) once the constant is
fixed to a particular value.
Our proposal, if true, might therefore resolve the long-standing
AdS/CFT discrepancies between gauge and string theory.
Posted by: KCL
A warm-up for solving noncompact sigma models: The Sinh-Gordon model
Joerg Teschner
(DESY Hamburg)
Abstract:
Standard methods like the Bethe ansatz will typically fail when the target space of an integrable model is non-compact like, for example, in the case of the nonlinear sigma models associated to AdS-spaces. New methods are needed. We will discuss some of them in the simplest possible example, the Sinh-Gordon model.
Standard methods like the Bethe ansatz will typically fail when the target space of an integrable model is non-compact like, for example, in the case of the nonlinear sigma models associated to AdS-spaces. New methods are needed. We will discuss some of them in the simplest possible example, the Sinh-Gordon model.
Posted by: KCL
A new paradigm for symmetry in viral architecture
Reidun Twarock
(University of York)
Abstract:
We show that the full three-dimensional architecture of simple viruses is encoded by affine symmetries. In particular, the locations and structures of all material boundaries can be predicted with our method, including the organisation of the capsid proteins and the genomic material. This approach departs radically from the 2-dimensional schematic representations of viral capsids in Caspar-Klug Theory and its recent generalisations, and opens up new possibilities to study the immuno-dominant epitopes and viral evolution. Applications to the modelling of virus assembly are also discussed, and we show that the counting of assembly pathways can be cast into a Hamiltonian paths problem
We show that the full three-dimensional architecture of simple viruses is encoded by affine symmetries. In particular, the locations and structures of all material boundaries can be predicted with our method, including the organisation of the capsid proteins and the genomic material. This approach departs radically from the 2-dimensional schematic representations of viral capsids in Caspar-Klug Theory and its recent generalisations, and opens up new possibilities to study the immuno-dominant epitopes and viral evolution. Applications to the modelling of virus assembly are also discussed, and we show that the counting of assembly pathways can be cast into a Hamiltonian paths problem
Posted by: CityU