Triangle Seminars
Monday, 3 Dec 2012
Higher-spin cubic interactions and holography
Euihun Joung
(SNS, Pisa)
Abstract:
Some issues of higher-spin (HS) gauge theory (in d+1>3) related to its cubic interactions and holography are discussed. After providing a very brief overview on the topic, I show how to construct all gauge consistent cubic interactions using the ambient-space formulation. Its number matches that of all possible 3pt functions, recently derived by other groups. However only one vertex corresponds to the free scalar CFT on the boundary, hence the metric-like version of the vertex encoded in Vasiliev's equation.
Some issues of higher-spin (HS) gauge theory (in d+1>3) related to its cubic interactions and holography are discussed. After providing a very brief overview on the topic, I show how to construct all gauge consistent cubic interactions using the ambient-space formulation. Its number matches that of all possible 3pt functions, recently derived by other groups. However only one vertex corresponds to the free scalar CFT on the boundary, hence the metric-like version of the vertex encoded in Vasiliev's equation.
Posted by: IC
Tuesday, 4 Dec 2012
t.b.a.
Nick Dorey
(DAMTP)
Wednesday, 5 Dec 2012
AdS/Ricci-flat correspondence
📍 London
Kostas Skenderis
(Southampton)
Abstract:
We show that for every asymptotically AdS solution compactified on a torus there is a corresponding Ricci-flat solution obtained by replacing the torus by a sphere, performing a Weyl rescaling of the metric and appropriately analytically continuing the dimension of the torus/sphere (as in generalized dimensional reduction). This correspondence should allow us to develop a holographic dictionary for Ricci-flat spacetimes. In particular, it maps Minkowski spacetime to AdS on a torus, the holographic stress energy tensor of AdS to the stress energy tensor due to a brane localized in the interior of spacetime and AdS black branes to (asymptotically flat) Schwarzschild black branes. Applying it to the known solutions describing the hydrodynamic regime in AdS/CFT, we compute the dispersion relation of the Gregory-Laflamme unstable modes through cubic order in the wavenumber, finding remarkable agreement with numerical data. We further obtain the fluid dual to Rindler spacetime and show that its transport coefficients through second order follow from the AdS ones.
We show that for every asymptotically AdS solution compactified on a torus there is a corresponding Ricci-flat solution obtained by replacing the torus by a sphere, performing a Weyl rescaling of the metric and appropriately analytically continuing the dimension of the torus/sphere (as in generalized dimensional reduction). This correspondence should allow us to develop a holographic dictionary for Ricci-flat spacetimes. In particular, it maps Minkowski spacetime to AdS on a torus, the holographic stress energy tensor of AdS to the stress energy tensor due to a brane localized in the interior of spacetime and AdS black branes to (asymptotically flat) Schwarzschild black branes. Applying it to the known solutions describing the hydrodynamic regime in AdS/CFT, we compute the dispersion relation of the Gregory-Laflamme unstable modes through cubic order in the wavenumber, finding remarkable agreement with numerical data. We further obtain the fluid dual to Rindler spacetime and show that its transport coefficients through second order follow from the AdS ones.
Posted by: KCL
Curved geometries for rigid supersymmetry
Davide Cassani
(King's College)
Abstract:
Supersymmetry on curved spaces has recently attracted much attention, mainly as a tool towards the exact computation of quantum field theory observables via localization. Taking a holographic perspective, I will discuss how the conditions for rigid supersymmetry to be preserved on a curved boundary arise from the bulk supergravity Killing spinor equations. In particular, I will show that a four-dimensional superconformal field theory can be put on a curved, Lorentzian spacetime if and only if this admits a null conformal Killing vector. For a supersymmetric field theory with an R-symmetry, not necessarily conformal, the vector is further restricted to be Killing. After having presented some illustrative examples, I will conclude comparing with the Euclidean case.
Supersymmetry on curved spaces has recently attracted much attention, mainly as a tool towards the exact computation of quantum field theory observables via localization. Taking a holographic perspective, I will discuss how the conditions for rigid supersymmetry to be preserved on a curved boundary arise from the bulk supergravity Killing spinor equations. In particular, I will show that a four-dimensional superconformal field theory can be put on a curved, Lorentzian spacetime if and only if this admits a null conformal Killing vector. For a supersymmetric field theory with an R-symmetry, not necessarily conformal, the vector is further restricted to be Killing. After having presented some illustrative examples, I will conclude comparing with the Euclidean case.
Posted by: IC