Triangle Seminars
Wednesday, 29 May 2013
Instability of extremal black holes
📍 London
Stefanos Aretakis
(Princeton)
Abstract:
In this talk I will show that gauge-invariant derivatives of scalar fields grow asymptotically along the event horizon of extremal black holes. This growth originates from conservation laws on such horizons. The resulted conserved quantities can be seen as a natural generalization of the Newman-Penrose constants along null infinity. I will also present recent generalizations by Reall and Lucietti concerning electromagnetic and linearized gravitational perturbations of extremal black holes.
In this talk I will show that gauge-invariant derivatives of scalar fields grow asymptotically along the event horizon of extremal black holes. This growth originates from conservation laws on such horizons. The resulted conserved quantities can be seen as a natural generalization of the Newman-Penrose constants along null infinity. I will also present recent generalizations by Reall and Lucietti concerning electromagnetic and linearized gravitational perturbations of extremal black holes.
Posted by: KCL
Thursday, 30 May 2013
D-Branes, Matrices and Emergent Space
Frank Ferrari
(ULB and International Solvay Institute)
Abstract:
We explain how to define, in matrix (gauge) field theory, the notion of the effective action of k ``probe'' branes in the presence of N ``background'' branes on which the field theory lives. The analysis of the large N planar diagram expansion which computes the effective action yields a simple and generic mechanism explaining the emergence of holographic space dimensions. The resulting effective action matches the non-abelian D-brane action in the closed string background dual to the field theory. We shall discuss briefly a few explicit examples, and also provide a general introduction to the notion of emerging space.
We explain how to define, in matrix (gauge) field theory, the notion of the effective action of k ``probe'' branes in the presence of N ``background'' branes on which the field theory lives. The analysis of the large N planar diagram expansion which computes the effective action yields a simple and generic mechanism explaining the emergence of holographic space dimensions. The resulting effective action matches the non-abelian D-brane action in the closed string background dual to the field theory. We shall discuss briefly a few explicit examples, and also provide a general introduction to the notion of emerging space.
Posted by: IC