Triangle Seminars
Tuesday, 25 Nov 2014
Massive Higher-Spin Gravities in 3d unfolded
📍 London
Dmitry Ponomarev
(LMU (Munich))
Abstract:
We classify the possible linear unfolded equations for propagating
bosonic higher-spin tensor fields in AdS_3 backgrounds. Doing this
we reproduce the existing topologically massive and new topologically
massive (higher)-spin systems whose content we clarify. We find systems
that generalise various critical gravities to higher-spins.
We classify the possible linear unfolded equations for propagating
bosonic higher-spin tensor fields in AdS_3 backgrounds. Doing this
we reproduce the existing topologically massive and new topologically
massive (higher)-spin systems whose content we clarify. We find systems
that generalise various critical gravities to higher-spins.
Posted by: KCL
Resolving the Structure of Black Holes
Nicholas Warner
(IPhT, Saclay and Southern California U.)
Wednesday, 26 Nov 2014
Applying Aristotelean logic to Double Field Theory
📍 London
George Papadopoulos
(King's College)
Abstract:
Is there a consistent patching for double manifolds? I shall demonstrate that the solution of the strong section condition leads to exact 3-form field strengths. I shall also prove that the consistency of the examples presented so far depends on the choice of the atlas, and so they are not general covariant. Then I shall suggest a new construction which resolves some of the puzzles and possibly specifies the appropriate spaces up to homotopy.
Is there a consistent patching for double manifolds? I shall demonstrate that the solution of the strong section condition leads to exact 3-form field strengths. I shall also prove that the consistency of the examples presented so far depends on the choice of the atlas, and so they are not general covariant. Then I shall suggest a new construction which resolves some of the puzzles and possibly specifies the appropriate spaces up to homotopy.
Posted by: KCL
Effective actions for fluids from holography and the membrane paradigm
Natalia Pinzani Fokeeva
(Amsterdam)
Abstract:
It is widely believed that hydrodynamics is the low energy effective theory of any quantum field theory. In this talk I will derive the local low energy effective action for uncharged dissipationless conformal fluids through holography. This can be achieved by solving a double-Dirichlet problem for linearised gravitational perturbations between the conformal boundary of a (4+1)-dimensional AdS-black brane background and a stretched horizon. Interestingly dissipationless fluid dynamics is captured by Goldstone bosons of the broken symmetries by the classical solution ending on the second boundary. I will discuss how the effective action approach might be inconsistent unless there is a coupling to a dissipative dynamical IR sector which for simplicity can be replaced by a membrane paradigm-like boundary condition on a stretched horizon and I will also comment on the limits of validity of this simplification.
It is widely believed that hydrodynamics is the low energy effective theory of any quantum field theory. In this talk I will derive the local low energy effective action for uncharged dissipationless conformal fluids through holography. This can be achieved by solving a double-Dirichlet problem for linearised gravitational perturbations between the conformal boundary of a (4+1)-dimensional AdS-black brane background and a stretched horizon. Interestingly dissipationless fluid dynamics is captured by Goldstone bosons of the broken symmetries by the classical solution ending on the second boundary. I will discuss how the effective action approach might be inconsistent unless there is a coupling to a dissipative dynamical IR sector which for simplicity can be replaced by a membrane paradigm-like boundary condition on a stretched horizon and I will also comment on the limits of validity of this simplification.
Posted by: IC
Three-dimensional black holes and descendants
Carmen Li
(Edinburgh)
Abstract:
We determine the most general three-dimensional vacuum spacetime with a negative cosmological constant containing a non-singular Killing horizon. We show that the general solution with a spatially compact horizon possesses a second commuting Killing field and deduce that it must be related to the BTZ black hole (or its near-horizon geometry) by a diffeomorphism. We show there is a general class of asymptotically AdS_3 extreme black holes with arbitrary charges with respect to one of the asymptotic-symmetry Virasoro algebras and vanishing charges with respect to the other. We interpret these as descendants of the extreme BTZ black hole.
We determine the most general three-dimensional vacuum spacetime with a negative cosmological constant containing a non-singular Killing horizon. We show that the general solution with a spatially compact horizon possesses a second commuting Killing field and deduce that it must be related to the BTZ black hole (or its near-horizon geometry) by a diffeomorphism. We show there is a general class of asymptotically AdS_3 extreme black holes with arbitrary charges with respect to one of the asymptotic-symmetry Virasoro algebras and vanishing charges with respect to the other. We interpret these as descendants of the extreme BTZ black hole.
Posted by: IC
Thursday, 27 Nov 2014
Interacting UV fixed points - from 4D quantum gauge theories to 4D quantum gravity
Daniel Litim
(Sussex U.)
Abstract:
It is commonly believed that for a quantum field theory to be fundamental,
its high-energy behaviour must be governed by an ultraviolet (UV) fixed
point. A very satisfying example is given by asymptotic freedom of QCD
where the UV fixed point is non-interacting. In this talk, I discuss the
existence of interacting UV fixed points in various quantum field theories,
in particular in four dimensions, both with and without gravity. Implications
for particle physics are also evaluated.
It is commonly believed that for a quantum field theory to be fundamental,
its high-energy behaviour must be governed by an ultraviolet (UV) fixed
point. A very satisfying example is given by asymptotic freedom of QCD
where the UV fixed point is non-interacting. In this talk, I discuss the
existence of interacting UV fixed points in various quantum field theories,
in particular in four dimensions, both with and without gravity. Implications
for particle physics are also evaluated.
Posted by: QMW