Triangle Seminars
Monday, 24 Jun 2013
Closed formulae for superstring tree amplitudes: Multiple zeta values and the Drinfeld associator
Oliver Schlotterer
(AEI Potsdam and DAMTP)
Abstract:
We discuss tree level scattering of any number of massless open superstring states on a worldsheet of disk topology. The entire state dependence of the tree amplitude can be expressed in terms of gauge theory subamplitudes from the point particle limit. The string corrections entering through momentum dependent integrals over the disk boundary can be disentangled from the YM seeds and analyzed separately. Their power series expansion in the string length and momenta involves multiple zeta values (MZVs). We review some mathematical background on MZVs and the network of relations between them. The explicit form of any tree level string correction to YM theory is derived from the generating function of MZVs – the Drinfeld associator. It interpolates between the worldsheet integrals in N-point and (N-1)-point scattering and leads to a recursive formula for the momentum expansion of any disk amplitude. Our results apply for any number of spacetime dimensions or supersymmetries and chosen helicity configurations.
We discuss tree level scattering of any number of massless open superstring states on a worldsheet of disk topology. The entire state dependence of the tree amplitude can be expressed in terms of gauge theory subamplitudes from the point particle limit. The string corrections entering through momentum dependent integrals over the disk boundary can be disentangled from the YM seeds and analyzed separately. Their power series expansion in the string length and momenta involves multiple zeta values (MZVs). We review some mathematical background on MZVs and the network of relations between them. The explicit form of any tree level string correction to YM theory is derived from the generating function of MZVs – the Drinfeld associator. It interpolates between the worldsheet integrals in N-point and (N-1)-point scattering and leads to a recursive formula for the momentum expansion of any disk amplitude. Our results apply for any number of spacetime dimensions or supersymmetries and chosen helicity configurations.
Posted by: IC
Wednesday, 26 Jun 2013
Thermodynamics of black M-branes from SCFTs
Shotaro Shiba
(KEK)
Abstract:
We discuss thermodynamics of N M2- and M5-branes by using the method proposed by Smilga and Wiseman, which explains the black Dp-brane thermodynamics from the maximally supersymmetric U(N) Yang-Mills theories. As result we obtain the consistent results with the predictions from the eleven-dimensional supergravity by very simple calculations: The free energy of M2-branes is evaluated by using ABJM theory as F ~ N^{3/2}k^{1/2}T^3, and that of M5-branes is estimated by assuming some natural properties of 6d conformal field theory as F ~ N^3T^6.
We discuss thermodynamics of N M2- and M5-branes by using the method proposed by Smilga and Wiseman, which explains the black Dp-brane thermodynamics from the maximally supersymmetric U(N) Yang-Mills theories. As result we obtain the consistent results with the predictions from the eleven-dimensional supergravity by very simple calculations: The free energy of M2-branes is evaluated by using ABJM theory as F ~ N^{3/2}k^{1/2}T^3, and that of M5-branes is estimated by assuming some natural properties of 6d conformal field theory as F ~ N^3T^6.
Posted by: IC
Thursday, 27 Jun 2013
Hitchin systems, spin chains from 3d mirror symmetry
Peter Koroteev
(Perimeter)
Abstract:
I will discuss some interesting connections between quantum and classical integrable systems (e.g. Hitchin system vs. quantum spin chains) in the context of 3 dimensional quiver gauge theories. Gauge theory dualities (Mirror symmetry, Seiberg duality) have direct counterparts on the integrability side.
I will discuss some interesting connections between quantum and classical integrable systems (e.g. Hitchin system vs. quantum spin chains) in the context of 3 dimensional quiver gauge theories. Gauge theory dualities (Mirror symmetry, Seiberg duality) have direct counterparts on the integrability side.
Posted by: IC