Thursday, April 30, 2015

62do encuentro de la Red Strings@ar

Tenemos el agrado de anunciar el 62do encuentro de la Red Strings@ar, que se realizará el miércoles 6 de mayo de 2015 en la Sala B del CCT La Plata, sito en Calle 8 Nro 1467 entre 62 y 63 de La Plata, 

El programa de este nuevo Encuentro será el siguiente: 

10:00 - 10:30  Welcome coffee 

10:30 - 11:30  Jeremías Aguilera-Damia 
Strings in AdS4 x CP3, Wilson loops in N=6 super Chern-Simons-matter and Bremsstrahlung functions 

We find 1/6 BPS string configurations in AdS4 x CP3, which we identify as the duals ofcertain 1/6 BPS circular  Wilson loops in N=6 superChern-Simons-matter gauge theory. We use our results to verify -in the strong coupling limit- a proposal made in arXiv:1402.4128 for a relation  between the expectation value of these  Wilson loops and the Bremsstrahlung function from deforming 1/2 BPS Wilson lines with a cusp. We  also derive an analogous relation  between theexpectation value of some particular 1/12 BPS Wilson loops and the Bremsstrahlung function from deforming 1/6 BPS Wilson lines with an internal space cusp.

11:30 - 13:30 Lunch break

13:30 - 14:30 Nicolas Grandi
Holographic Thermalization of Charged operators  

We study a light-like charged collapsing shell in AdS-Reissner-Nordstrom spacetime, investigating whether the corresponding Vaidya metric is supported by matter that satisfies the null energy condition. We find that, if the absolute value of the charge decreases during the collapse, energy conditions are fulfilled everywhere in spacetime. On the other hand, if the absolute value of the charge increases, the metric does not satisfy energy conditions in the IR region. Therefore, from the gauge/gravity perspective, this last case is only useful to study the thermalization of the UV degrees of freedom. For all these geometries, we probe the thermalization process with two point correlators of charged operators, finding that the thermalization time grows with the charge of the operator, as well as with the dimension of space.

14:30 - 15:30 Alan Garbarz

15:30 - 16:00  Coffee break

16:00 - 17:00 Julio Oliva
Black Strings in Gauss-Bonnet are Unstable

We report the existence of unstable, s-wave modes, for black strings in Gauss-Bonnet theory (which is quadratic in the curvature) in seven dimensions. This theory admits analytic uniform black strings that in the transverse section are black holes of the same Gauss-Bonnet theory in six dimensions. All the components of the perturbation can be written in terms of a single one and its derivatives. For this latter component we find a master equation which admits bounded solutions provided the characteristic time of the exponential growth of the perturbation is related with the wave number along the extra direction, as it occurs in General-Relativity. It is known that these configurations suffer from a thermal instability, and therefore the results presented here provide evidence for the Gubser-Mitra conjecture in the context of Gauss-Bonnet theory. Due to the non-triviality of the curvature of the background, all the components of the metric perturbation appear in the linearized equations. As it occurs for spherical black holes, these black strings should be obtained as the short distance r<<\alpha^{1/2} limit of the black string solution of Einstein-Gauss-Bonnet theory, which is not know analytically, where \alpha is the Gauss-Bonnet coupling.

Esperamos verlos en el encuentro de Strings@ar el miércoles 6 de mayo

Cordiales saludos,

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