Relativistický seminář
Ústavu teoretické fyziky


Seminář se koná v úterý ve 13:10 v posluchárně ÚTF MFF UK
v 10. patře katedrové budovy v Tróji, V Holešovičkách 2, Praha 8


Příští semináře:

5. května 2015
Hamiltonian dynamics with constraints
Jakub Pejcha
ÚTF
(seminář v angličtině)

In proceeding from Lagrangian to Hamiltonian, it may happen that not all momenta are independent functions of the velocities, so one cannot express all velocities as functions of momenta and coordinates only. One thus gets constraints. In this seminar we show how to write down eguations of motion in such a case. We introduce the notion of Dirac brackets, apply the formalism to two simple Lagrangians and also compute the relativistic particle in flat space-time.

12. května 2015
On algebraically special Kaluza-Klein reductions
Tomáš Tintěra
Matematický ústav AV ČR, Praha
(seminář v angličtině)
19. května 2015
Progress in the numerical treatment of collapsing gravitational waves
dr. David Hilditch
Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena, Germany
(seminář v angličtině)

(Second part of a mini-course on numerical relativity:) In 1993 Abrahams and Evans presented numerical simulations of gravitational waves. They evolved members of one-parameter families of initial data which either settled to flat-space or collapsed to form a black hole if the strength parameter was sufficiently large. Tuning to the threshold of black-hole formation they found evidence of critical behavior. Despite several attempts this result has not been reproduced. In this talk I will discuss a new attack on the problem.

20. května 2015
POZOR, mimořádně STŘEDA (13:10)
Hyperbolicity of constrained Hamiltonian systems
dr. David Hilditch
Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena, Germany
(seminář v angličtině)

In my last talk I will focus on the principle question: what is the consequence of the gauge freedom of general relativity in building free-evolution formulations for numerical relativity.


Minulé semináře:

24. února 2015
GHP formalism in the cosmological perturbation theory
Jan Novák
Matematický ústav AV ČR, Praha
(seminář v angličtině)

3. března 2015
Numerical evolution of gravitational-wave collapse
Anton Khirnov
ÚTF
(seminář v angličtině)
10. března 2015
Weak electromagnetic field admitting integrability in Kerr-NUT-(A)dS spacetimes
Ivan Kolář
ÚTF
17. března 2015
(Anti-)de Sitterův vesmír v Plebańského–Demiańského souřadnicích
Ondřej Hruška
ÚTF
24. března 2015
Existence of Reissner-Nordström--type black holes in f(R) gravity
Morteza Kerachian
ÚTF
(seminář v angličtině)
31. března 2015
Universal spacetimes
dr. Vojtěch Pravda
Matematický ústav AV ČR, Praha
(seminář v angličtině)
7. dubna 2015
Seminář se nekoná
14. dubna 2015
Biconformal symmetry and a closed form for static Green functions in black holes and in homogeneous background spacetimes
dr. Andrei Zelnikov
Theoretical Physics Institute, Department of Physics, University of Alberta, Edmonton
(seminář v angličtině)

We study static scalar and Maxwell fields created by a source in a static D-dimensional spacetime. We demonstrate that the corresponding equation for these field is invariant under a special transformation of the background metric. This transformation consists of the static conformal transformation of the spatial part of the metric accompanied by a properly chosen transformation of the red-shift factor. Both transformations are determined by one function of the spatial coordinates. We show that in a case of higher dimensional spherically symmetric black holes one can find such a bi-conformal transformation that the symmetry of the D-dimensional metric is enhanced after its application. Namely, the metric becomes a direct sum of the metric on a unit sphere and the metric of the anti-de Sitter space. The method of the heat kernels allows one to obtain static Green functions in the original space of the static black hole. The general useful representation of static Green functions is obtained in the Schwarzschild-Tangherlini spacetimes of arbitrary dimension. Using this method we obtained the exact closed form for the potentials of massless scalar and Maxwell fields created by static charges near four- and five-dimensional charged black holes.

21. dubna 2015
Cesty za horizont (deformovaného Schwarzschilda)
Marek Basovník
ÚTF
28. dubna 2015
Firewall paradox
Martin Scholtz
ÚTF
(seminář v angličtině)

In 2012, Almheiri, Marolf, Polchinski and Sully (AMPS) published a surprising result that the equivalence principle is in conflict with the assumption that the information is conserved during the black hole formation and evaporation. In standard GR, an observer freely falling into the black hole does not encounter anything unusual, while AMPS argue that such an observer will be burnt by a firewall. The aim of the seminar is to provide a brief introduction to the firewall paradox and to present the argumentation of AMPS.


Předchozí ročníky:


Jiří Bičák                                                                                                  Oldřich Semerák


© 28. dubna 2015; Oldřich Semerák <semerak@mbox.troja.mff.cuni.cz>
© 4. května 2015; vygenerováno pomocí aplikace seminar, verze 2.04 (2003-09-02); správce <Pavel.Krtous@mff.cuni.cz>