Triangle Seminars
Tuesday, 1 Dec 2009
Quantum Gravity and Signatures of noncommutative spacetime
Richard Szabo
(Heriot-Watt University, Edinburgh )
Abstract:
A pedagogical introduction into the ideas, propects and successes of spacetime quantization will be presented, with emphasis on what it tells us about hte problems of quantizing gravity and renormalizing quantum field theory.
A pedagogical introduction into the ideas, propects and successes of spacetime quantization will be presented, with emphasis on what it tells us about hte problems of quantizing gravity and renormalizing quantum field theory.
Posted by: KCL
Avoiding the characteristic function in the supersymmetry method
Mario Kieburg
(Univ. Duisburg-Essen)
Wednesday, 2 Dec 2009
Ultraviolet Structure of Maximal Supersymmetric Theories
📍 London
Kelly Stelle
(Imperial)
Local E11 and gauged maximal supergravities
Fabio Riccioni
(KCL)
Abstract:
We give a method of deriving the field-strengths of all massless and massive, i.e. gauged, maximal supergravity theories in any dimension starting from the Kac-Moody algebra E11. Considering the subalgebra of E11 that acts on the fields in the non-linear realisation as a global symmetry, we show how this is promoted to a gauge symmetry enlarging the algebra by the inclusion of additional generators. Given the enlarged algebra corresponding to the massless theory, we show that this can be deformed to obtain the algebra corresponding to the gauged theory. We show how this works in detail for the case of Scherk-Schwarz reduction of IIB to nine dimensions. We then classify all the possible deformations in any dimensions and show that these are in one to one correspondence with all the possible gauged supergravities. This provides a very efficient, simple and unified derivation of the field strengths and gauge transformations of all the bosonic fields of any maximal supergravity theory.
We give a method of deriving the field-strengths of all massless and massive, i.e. gauged, maximal supergravity theories in any dimension starting from the Kac-Moody algebra E11. Considering the subalgebra of E11 that acts on the fields in the non-linear realisation as a global symmetry, we show how this is promoted to a gauge symmetry enlarging the algebra by the inclusion of additional generators. Given the enlarged algebra corresponding to the massless theory, we show that this can be deformed to obtain the algebra corresponding to the gauged theory. We show how this works in detail for the case of Scherk-Schwarz reduction of IIB to nine dimensions. We then classify all the possible deformations in any dimensions and show that these are in one to one correspondence with all the possible gauged supergravities. This provides a very efficient, simple and unified derivation of the field strengths and gauge transformations of all the bosonic fields of any maximal supergravity theory.
Posted by: IC
Thursday, 3 Dec 2009
Yangian symmetry and a new regularization of scattering amplitudes in N=4 SYM
Jan Plefka
(Humboldt University)
Abstract:
In this talk we will review the appearance of an infinite dimensional symmetry algebra
of tree level scattering amplitudes of N=4 super Yang-Mills theory, known as the Yangian
of psu(2,2 4). It arises through the commutation of standard superconformal and the recently
discovered dual superconformal symmetries of scattering amplitudes. At the loop level the
conformal and dual conformal symmetry is destroyed by infrared divergencies. The present challenge
is whether it may be repaired. We point out a novel IR regularization based on a suitable Higgsing of
the theory, which is natural from the dual string perspective. It turns out that in this regularization
an extended conformal symmetry of the loop amplitudes arises, which remains free of anomalies.
In this talk we will review the appearance of an infinite dimensional symmetry algebra
of tree level scattering amplitudes of N=4 super Yang-Mills theory, known as the Yangian
of psu(2,2 4). It arises through the commutation of standard superconformal and the recently
discovered dual superconformal symmetries of scattering amplitudes. At the loop level the
conformal and dual conformal symmetry is destroyed by infrared divergencies. The present challenge
is whether it may be repaired. We point out a novel IR regularization based on a suitable Higgsing of
the theory, which is natural from the dual string perspective. It turns out that in this regularization
an extended conformal symmetry of the loop amplitudes arises, which remains free of anomalies.
Posted by: QMW