Relativity Seminar
of the Department of Theoretical Physics

Seminar is held on Tuesdays at 13:10 pm in the lecture room of the Institute
on the 10th floor of the department building at Trója, V Holešovičkách 2, Prague 8

Next seminars:

October 30, 2018
(seminar in Czech language)
November 6, 2018
Propagators of the wave equation on low-regularity spacetimes
Dr. Yafet Erasmo Sanchez Sanchez
Max Planck Institute for Mathematics, Bonn

I will define classical and non-classical solutions of the wave equation. I will give some motivations about why low regularity scenarios are interesting. Finally, I will focus on the classical ones and discuss their relationship with quantum field theory in spacetimes with limited regularity.

Previous seminars:

July 24, 2018
The type D and the near-horizon geometry equations
Prof. Jerzy Lewandowski
Institute of Theoretical Physics, University of Warsaw
September 25, 2018
skype seminar
Black holes as probes of fundamental physics
Robert Benkel
University of Nottingham, UK
September 27, 2018
!!! Thursday from 13:10 !!!
Shadow of black holes at cosmological distances
Dr. Oleg Yu. Tsupko
Space Research Institute of Russian Academy of Sciences, Moscow
October 2, 2018
Remarks on ghost-free theories
Prof. Valeri P. Frolov
Department of Physics, University of Alberta, Edmonton
October 5, 2018
!!! FRIDAY from 13:10 !!!
Gravitational-wave astrophysics: a new era of discovery
Dr. Jessica McIver
California Institute of Technology
October 5, 2018
!!! FRIDAY, from 16:20 !!!
Hyperbolicity of relativistic fluids
Dr. David Hilditch
Centro Multidisciplinar de Astrofisica, IST, University of Lisbon

I will discuss conditions for the well-posedness of the initial value problem for evolution type PDEs. Well-posedness is a necessary condition for any numerical approximation to converge in the limit of infinite resolution. The crucial condition is that of strong-hyperbolicity. I will then consider various fluid models and highlight in particular the difficulties faced in particular in the modeling of stars. Several popular formulations of MHD turn out to be ill-posed.

October 9, 2018
Derrick’s theorem on curved spacetime and the stability of relativistic stars in modified gravity
Dr. Sante Carloni
Centro Multidisciplinar de Astrofisica, IST, University of Lisbon

I will present a generalisation of Derick theorem to the case of curved spacetime. As a consequence of this generalisation, relativistic boson stars are proved to be always unstable. Derrick’s theorem has profound consequences also on modified gravity, and in particular on theories with an additional scalar degrees of freedom. I will comment extensively on these consequences.

October 16, 2018
The next big thing: extreme-mass-ratio inspiral
(Impressions from 2018 Capra conference)
Dr. Tomáš Ledvinka
October 23, 2018
Uniformly accelerating, yet standing still
(On boost-rotation, topology of G-->0 limit of C-metric, higher dimensions, and linearized gravity)
Dr. David Kofroň

The search for the C-metric in higher dimensions is still unsuccessful and ongoing project. I wanted, also unsuccessfully, to find a simple solution to general boost-rotation symmetric metric in higher dimensions (generalization of Bonnor-Swaminayaran solutions). Finally I ended up in the linearized gravity to gain some insight in this topics and to learn some lessons. Based on work in progress this would be more discussion open seminar than a lecture.

Previous semesters:

Jiří Bičák                                                                                                  Oldřich Semerák

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