Relativistický seminář
Ústavu teoretické fyziky

podzim 2014

Proběhlé semináře:

14. října 2014
Relativistic gravothermal instabilities
Dr. Zacharias Roupas
School of Applied Mathematics and Physical Sciences, National Technical University of Athens
(seminář v angličtině)

The instabilities of the self-gravitating, relativistic, ideal gas to all temperature and density regimes are studied in the case of static, spherically symmetric spacetime. For an ideal gas, thermal energy is the only one that can halt gravitational collapse. However, since thermal energy gravitates as well, it can also cause gravitational collapse at high energies. Hence, we anticipate to find two instabilities for a bounded sphere that contains relativistic gas. One at low energies, where thermal energy becomes too weak to halt gravity, and another at high energies, where gravity becomes too strong to be halted by thermal pressure even if it is high, as well. The two energy limits correspond also to radius limits. So that, stable static configurations exist only in between two marginal radii for any fixed energy with negative gravothermal (thermal plus gravitational) energy. For positive gravothermal energy, there is only one maximum energy and one minimum radius. All these turning points of stability are found to depend on the total number of particles, i.e. on the rest mass. Relativistic, ultimate limits of rest mass, total mass and radius are found. Regarding the rest mass, stable equilibria exist only for: Mrest < 0.35 Ms, where Ms is the Schwarzschild mass. For total mass M and radius R, the relativistic, ultimate limit for stability is 2GM/Rc2 < 0.44.

21. října 2014
Volume and area operators in quantum Einstein-Cartan theory
Dr. Marián Pilc
(seminář v angličtině)

Kinematic Hilbert space in QECT is constructed via von Neumann infinite dimensional tensor product of point Hilbert spaces. The Hilbert space of this kind is too big therefore we need to pick up its certain subspace which mimics underlying manifold structure of spatial section in better way. This enables us to define measures with values in operator algebra (bounded and unbounded cases are considered) which are absolutely continuous with respect to Lebesgue - coordinate measure over spatial section. This general construction helps us to define Volume and Area operators in QECT.

4. listopadu 2014
De Rham complex twisted by the oscillator bundle
Dr. Svatopluk Krýsl
Matematický ústav UK
(seminář v angličtině)
11. listopadu 2014
Ilustrace warpové metriky
Rico Gattermann
18. listopadu 2014
Geodetická struktura prostoročasů s více černými dírami
Jiří Ryzner
25. listopadu 2014
Chaos kolem černých děr s disky a prstenci: (pseudo-)newtonovsky
Vojtěch Witzany
2. prosince 2014
Self-force computation and Extreme Mass Ratio Inspirals
dr. Patxi Ritter
University of Orleans, France
(seminář v angličtině)
9. prosince 2014
Volume and area operators in quantum Einstein-Cartan theory - II
dr. Marián Pilc
ÚTF, UniCredit Bank

Další ročníky:

© 15. prosince 2014; Oldřich Semerák <>
© 2. října 2022; vygenerováno pomocí aplikace seminar, verze 2.04 (2003-09-02); správce <>