Triangle Seminars
Monday, 20 Feb 2006
tba
Dan Waldram
(Imperial)
Tuesday, 21 Feb 2006
Collisions of Strings with Y Junctions
Tom Kibble
(Imperial College)
Abstract:
I will discuss the dynamics of Nambu–Goto strings with junctions at which three strings meet, in particular, the process of intercommuting of two straight strings, in which they exchange partners but become joined by a third string. I shall show that there are important kinematical constraints on this process. The exchange cannot occur if the strings meet with very large relative velocity. In the case of non-abelian strings, there is also a possibility that they can get locked, unable to separate in any direction. This may have important implications for the evolution of cosmic superstring networks and non-abelian string networks.
I will discuss the dynamics of Nambu–Goto strings with junctions at which three strings meet, in particular, the process of intercommuting of two straight strings, in which they exchange partners but become joined by a third string. I shall show that there are important kinematical constraints on this process. The exchange cannot occur if the strings meet with very large relative velocity. In the case of non-abelian strings, there is also a possibility that they can get locked, unable to separate in any direction. This may have important implications for the evolution of cosmic superstring networks and non-abelian string networks.
Posted by: IC
Wednesday, 22 Feb 2006
Extremal single charge small black holes
📍 London
Aninda Sinha
(Cambridge)
Spectral properties of quantum spin-chains of Temperley-Lieb type
Britta Aufgebauer
(Bergische Universitaet Wuppertal)
Abstract:
The abstract can be found at
http://www.city.ac.uk/sems/mathematics/seminars.html
The abstract can be found at
http://www.city.ac.uk/sems/mathematics/seminars.html
Posted by: CityU
Thursday, 23 Feb 2006
On T-folds and Supersymmetry
Emily Hackett-Jones
(Edinburgh)
Stationary Spacetime from Intersecting M-branes
Makoto Tanabe
(Tokyo)
Abstract:
We study a stationary black brane in M-superstring theory. Assuming BPS-type relations between
the first-order derivatives of metric functions, we present general stationary black brane
solutions with a traveling wave for the Einstein equations in D-dimensions. The solutions are
given by a few independent harmonic equations (and plus the Poisson equation). General
solutions are constructed by superposition of a complete set of those harmonic functions. Using
the hyperspherical coordinate system for a conformally flat base space, we explicitly give the
solutions in 11-dimensional M-theory for the case with M2-M5 intersecting branes and a
traveling wave. Compactifying these solutions into five dimensions, we show that these
solutions include the BMPV black hole and the Brinkmann wave solution, and those extension to
non-BPS ones. We also find new solutions similar to the Brinkmann wave. We prove that the
solutions preserve the one eigth supersymmetry if the gravi-electromagnetic field, which is a
rotational part of gravity, is self-dual. We also discuss non-spherical black objects (e.g., a
ring topology and an elliptical shape) by use of other curvilinear coordinates.
We study a stationary black brane in M-superstring theory. Assuming BPS-type relations between
the first-order derivatives of metric functions, we present general stationary black brane
solutions with a traveling wave for the Einstein equations in D-dimensions. The solutions are
given by a few independent harmonic equations (and plus the Poisson equation). General
solutions are constructed by superposition of a complete set of those harmonic functions. Using
the hyperspherical coordinate system for a conformally flat base space, we explicitly give the
solutions in 11-dimensional M-theory for the case with M2-M5 intersecting branes and a
traveling wave. Compactifying these solutions into five dimensions, we show that these
solutions include the BMPV black hole and the Brinkmann wave solution, and those extension to
non-BPS ones. We also find new solutions similar to the Brinkmann wave. We prove that the
solutions preserve the one eigth supersymmetry if the gravi-electromagnetic field, which is a
rotational part of gravity, is self-dual. We also discuss non-spherical black objects (e.g., a
ring topology and an elliptical shape) by use of other curvilinear coordinates.
Posted by: IC