[hep-th] seminar

[Branislav Cvetkovic]

Postovane kolege,

u petak 15. decembra u 11 h  na Institutu za fiziku Nelson Merino 
(Université Paris-Diderot) ce odrzati seminar
pod naslovom  "Transgressions, boundary terms and Katz-like vectors in 
Lovelock gravity". Apstrakt vam prosledjujem u
nastavku.

Pozdrav Branislav


APC Laboratory, Paris 7
Paris, France



Abstract: The divergence of the Katz vector provides a
non-equivalent alternative to the Gibbons-Hawking-York (GHY) term,
allowing to have a well-posed variational principle in General
Relativity. It is constructed in terms of the metric and the
difference of the Christoffel symbols of the dynamical and background
manifolds. Unlike the GHY term, which was generalized by Myers to the
case of Lovelock gravity, the Katz formulation is performed only in
tensorial language and, up to now, it was not known how to generalize
it to more general theories.
In this work we provide a way to write the Katz vector by means of a
local Lorentz-covariant construction. In particular, we show that the
Katz vector in Einstein-Hilbert gravity can be obtained as a
dimensional continuation of a transgression form, which is a function
of two suitable Lorentz connections. Then we generalize this result to
the case of Einstein-Gauss-Bonnet gravity and show that the
corresponding generalized Katz vector solves the Dirichlet problem and
gives the correct mass for the Boulware-Deser black hole. After
discussing and contrasting this result with the ones already known in
the literature, we show how a Katz-like vector can be constructed for
a generic Lovelock theory.

Based on:_ arXiv:1709.06478 and a work in progress.

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