Relativity Seminar
of the Institute of Theoretical Physics

fall 2010


Given seminars:

August 2, 2010
Monday (!) 13:10, ITF
Gauss-Bonnet black holes with symmetry
Hideki Maeda
Centro de Estudios Cientificos, Chile
October 12, 2010
Characteristic sound of black-hole disk accretion
dr. Jiří Horák
PRA Group, Astronomical Institute of AS CR
(seminar in Czech language)
October 19, 2010
Ultraspinning instability of black holes
dr. Oscar Dias
Relativity & Gravitation Group, DAMTP, University of Cambridge

We present the first example of a linearized gravitational instability of an asymptotically flat vacuum black hole: the ultraspinning instability first conjectured to exist by Emparan and Myers. We study perturbations of a Myers-Perry black hole 1) with a single spin and 2) with equal angular momenta. In the singly spinning case we find the stationary perturbations that mark the onset of the instability and the appearance of the new pinched black hole phases that are conjectured to connect to the black ring and black Saturn families. We further analyse the asymptotically AdS case, and determine the onset of the instability as a function of the cosmological constant. For the equal spin case, we find perturbations that grow exponentially in time and the dispersion relation of the instability. The onset of the instability is associated with the appearance of time-independent perturbations which generically break all but one of the rotational symmetries. This is interpreted as evidence for the existence of a new 20-parameter family of black hole solutions with only a single rotational symmetry, ie that saturate Hawking's rigidity theorem. We also present results for the Gregory-Laflamme instability of rotating black strings, demonstrating for the first time that rotation makes black strings more unstable. Finally, we establish a formal connection between this classical instability and thermodynamics that provides a "thermodynamic candle" to anticipate the possible existence of this instability in other black holes.

October 26, 2010
Kerr / CFT correspondence
Matěj Kudrna
ÚTF / FzÚ AV ČR
(seminar in Czech language)
November 2, 2010
Particle motion in the vicinity of compact objects / Triple gravitational microlens
Jan Čechura / Kamil Daněk
AsÚ AV ČR / ÚTF
(seminar in Czech language)
November 9, 2010
Action at distance - GTR for a working day
Tomáš Ledvinka
ÚTF
(seminar in Czech language)
November 16, 2010
Zážitky z pádu do černé díry / Cylindrické zdroje gravitačních vln
Anton Khirnov / Aleš Turnovec
ÚTF
(seminar in Czech language)
November 23, 2010
Twin paradox in general relativity / On convergence of perturbation series in stationary axisymmetric case
Jiří Daněk / Pavel Čížek
ÚTF
(seminar in Czech language)
November 30, 2010
seminář se nekoná
(seminar in Czech language)
December 7, 2010
Charged particles in EM field on Kerr background, chaos and symplectic integrators
Ondřej Kopáček
skupina relativistické astrofyziky, AsÚ AV ČR
(seminar in Czech language)
December 14, 2010
Charged particles in EM field on Kerr background, chaos and symplectic integrators - II
Ondřej Kopáček
skupina relativistické astrofyziky, AsÚ AV ČR
(seminar in Czech language)
January 11, 2011
Post-Newtonian Hamiltonians and spin effects in general relativity
dr. Jan Steinhoff
Institute of Theoretical Physics, F. Schiller University in Jena

Other semesters:


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