Seminars
Our seminars take place in the library of the Main Building (Praha–Sporilov, see
Contacts).
Scheduled:
29.09.2009 14:00
Fernando de Felice
University of Padova, Italy
Why dark matter is
dark?
Abstract
Fernando de Felice
Why dark matter is dark?
Introducing the concepts of space- and time-velocities we can formulate a Generalized Principle of Relativity which states that any particle has a world-velocity equal to the Maxwell's constant c with respect to any observer. We propose that dark matter has time-velocity equal to zero and discuss the possible implications.
Previous:
20.07.2009 14:00
Tapas K. Das
Harish Chandra Research Institute, Allahabad, India
On the multi-critical properties of axisymmetric matter flow in the Kerr metric
Abstract
Tapas K. Das
On the multi-critical properties of axisymmetric matter flow in the Kerr metric
I will demonstrate that the accretion of non self-gravitating classical fluid onto astrophysical black holes may have multiple critical points by identifying the equations describing the space gradient of the dynamical flow velocity of the accreting matter to be equivalent to first order autonomous dynamical systems. Fixed point analysis ensures that such a flow must be multi-transonic for certain astrophysically relevant initial boundary conditions, and such multi-transonic flow allows the formation of Rankine-Hugoniot shock in the accretion disc. I also plan to demonstrate how such multi-transonic shocked flow model can be applied to explain various astrophysical phenomena, like generation of the AGN outflow and the X-ray flares from our Galactic centre, or the origin of the quasi periodic oscillations of black hole candidates.
We try hard to meet regularly to discuss ongoing research projects and recent astro-ph papers.
If you would like to give a seminar in our group, please contact Vladimir Karas.
Everybody is welcome.
Archive
2009,
2008,
2007,
2006,
2005,
2004
