Talk detail

Participant	Volkov , Michael
Institution	University of Tours - Parc de Grandmont - Tours - Region Centre - France

Session	AT4	Accepted		Order	Time
Talk	Oral abstract	Title	Massive spin-2 field in arbitrary spacetimes
Coauthors
Abstract	We present the consistent theory of a free massive spin-2 field with 5 degrees of freedom propagating in spacetimes with an arbitrary geometry. We obtain this theory via linearizing the equations of the ghost-free massive gravity expressed in the tetrad formalism. The theory is parameterized by a {\it non-symmetric} rank-2 tensor whose 16 components fulfill 11 constraints implied by the equations. When restricted to Einstein spaces, the theory reproduces the standard description of massive gravitons. In generic spacetimes, the theory does not show the massless limit and always propagates five degrees of freedom, even for the vanishing mass parameter. We illustrate these features by an explicit calculation for a homogeneous and isotropic cosmological background. It turns out that the spin-2 particles are always stable if they are sufficiently massive, hence they may be a part of the Dark Mater.
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Session	AT3	Accepted		Order	Time
Talk	Oral abstract	Title	Weyl metrics and wormholes
Coauthors
Abstract	We apply duality rotations and complexifications to the vacuum Weyl metrics generated by massive rods or by point masses. As a first step this gives families of prolate and oblate vacuum metrics. Further duality transformations produce a scalar field from the vacuum, which can be either the conventional scalar or the phantom field with negative kinetic energy. This gives rise to large classes of static, axially symmetric solutions, presumably including all previously known solutions for gravity-coupled massless scalar field. Especially interesting are the oblate solutions which, irrespectively of whether they are coupled to a scalar or not, describe wormholes connecting several asymptotic regions. In the one-wormhole sector they reduce to the ring wormholes in the vacuum case and to the Bronnikov-Ellis wormhole in the phantom case. We study the two-wormhole solutions and find that two of their four asymptotic regions are completely regular while two others contain an infinitely long strut along the symmetry axis.
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