Triangle Seminars
Monday, 24 Jan 2005
Closed bosonic string field theory at quartic order
📍 London
Nicolas Moeller
(King's College London)
Abstract:
I will explain how to do concrete computations in bosonic closed string
field theory. For this, I will show how to numerically describe the
geometry of the four-point contact interaction, by computing the boundary
of the relevant region of the moduli space of the four-punctured spheres,
and by computing everywhere in this region the local coordinates around
each punctures, in terms of a Strebel quadratic differential and mapping
radii. I will then explain how these results are used and checked in the
recent paper of Yang and Zwiebach by considering marginal fields in closed
bosonic string field theory.
I will explain how to do concrete computations in bosonic closed string
field theory. For this, I will show how to numerically describe the
geometry of the four-point contact interaction, by computing the boundary
of the relevant region of the moduli space of the four-punctured spheres,
and by computing everywhere in this region the local coordinates around
each punctures, in terms of a Strebel quadratic differential and mapping
radii. I will then explain how these results are used and checked in the
recent paper of Yang and Zwiebach by considering marginal fields in closed
bosonic string field theory.
Posted by: KCL
Wednesday, 26 Jan 2005
Twisted reflections on twisted SU(2n+1) branes
📍 London
Rafal R. Suszek
(King's College and Warsaw U.)
Abstract:
Chosen aspects of twisted brane geometry in the Wess-Zumino-Witten models
of type A_2n shall be discussed, both classical and stringy, in
reference to a class of coideal subalgebras of Drinfel'd-Jimbo quantum
groups known as twisted orthogonal quantum groups. An explicit relation
between the two families of algebras, together with a realisation of the
latter as (twisted) Reflection Equation Algebras shall be invoked to
emphasise the role played by them in a compact algebraic description of
quantum twisted branes on SU(2n+1) in the framework of R-matrix Reflection
Equations and associated quantum group geometries.
Chosen aspects of twisted brane geometry in the Wess-Zumino-Witten models
of type A_2n shall be discussed, both classical and stringy, in
reference to a class of coideal subalgebras of Drinfel'd-Jimbo quantum
groups known as twisted orthogonal quantum groups. An explicit relation
between the two families of algebras, together with a realisation of the
latter as (twisted) Reflection Equation Algebras shall be invoked to
emphasise the role played by them in a compact algebraic description of
quantum twisted branes on SU(2n+1) in the framework of R-matrix Reflection
Equations and associated quantum group geometries.
Posted by: KCL
Crosslinking Structures, The cunning tricks of the bugs uncovered
Reidun Twarock
(City University)
Thursday, 27 Jan 2005
All-genus calculation of Wilson loops using D-branes
Nadav Drukker
(Niels Bohr Institute)
Abstract:
The standard prescription for calculating a Wilson loop in the AdS/CFT correspondence is by a string world-sheet ending along the loop at the boundary of AdS. For a multiply wrapped Wilson loop this leads to many coincident strings, which may interact among themselves. In such cases a better description of the system is in terms of a D3-brane carrying electric flux. We find such solutions for the single straight line and the circular loop. The action agrees with the string calculation at small coupling and in addition captures all the higher genus corrections at leading order in alpha'. The resulting expression is in remarkable agreement with that found from a zero dimensional Gaussian matrix model.
The standard prescription for calculating a Wilson loop in the AdS/CFT correspondence is by a string world-sheet ending along the loop at the boundary of AdS. For a multiply wrapped Wilson loop this leads to many coincident strings, which may interact among themselves. In such cases a better description of the system is in terms of a D3-brane carrying electric flux. We find such solutions for the single straight line and the circular loop. The action agrees with the string calculation at small coupling and in addition captures all the higher genus corrections at leading order in alpha'. The resulting expression is in remarkable agreement with that found from a zero dimensional Gaussian matrix model.
Posted by: IC
Friday, 28 Jan 2005
Q-Fano 3-folds, K3 surfaces and mirrors
Alessio Corti
(Cambridge)
Abstract:
I want to study Q-Fano 3-folds from the point of view of
mirror symmetry. In this talk I make some remarks and try some
questions.
I want to study Q-Fano 3-folds from the point of view of
mirror symmetry. In this talk I make some remarks and try some
questions.
Posted by: KCL