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

- October 15, 2019
- Null surfaces, boundary action and thermodynamics
*Dr. Sumanta Chakraborty*- School of Physical Sciences and School of Mathematical and Computational Sciences, Indian Association for the Cultivation of Science, Kolkata, India
In the first part of my talk I will discuss the variational principle for general relativity and some associated subtle facts. In particular, I will try to arrive at the correct action principle for general relativity in presence of null boundaries. Possible generalization to Lovelock theories will also be presented. In the second part of my talk, I will discuss the thermodynamics of null surfaces. In particular, I will show that three different projections of gravitational momentum related to an arbitrary null surface in the space time leads to three different equations, all of which have thermodynamic interpretations.

- October 22, 2019
- Contrary inferences for classical histories in the consistent histories approach
*Dr. Adamantia Zampeli*- ITP
In this talk, I will discuss the problem which arises by the existence of zero cover measures in the classical limit of the consistent histories approach of quantum theory. I will analyze the time-of-arrival of a (semi-) classical free particle in an infinite square well and I will show how we end up with contrary inferences.

- October 29, 2019
- Equivalence and symmetry of teleparallel gravity
*Dr. David D. McNutt*- Department of Mathematics and Physics, Faculty of Science and Technology, University of Stavanger, Norway
A notable class of torsionful but curvatureless gravitational theories of gravity, known as teleparallel theories of gravity (or teleparallel gravity in brief), arise from assuming that both the non-metricity and the curvature of the affine connection are zero. Teleparallel theories of gravity have a long history of analysis, including Einstein himself who believed that the space of distant parallelism, (also called ``absolute parallelism'' or ``tele-parallelism'' by others) was the most promising candidate to unify gravitation and electromagnetism. Intriguingly, there exists a subclass of teleparallel theories of gravity that are dynamically equivalent to general relativity.

In teleparallel gravity and its generalizations, a frame basis replaces the metric as the central object of study, although the metric can still be constructed from the frame basis. Consequently, the concept of an isometry as a symmetry of the metric may no longer act as a symmetry of a solution to a given teleparallel gravity theory. However, for any teleparallel gravity solution, the set of symmetries are related to the set of invariants and studying the set of invariants will provide information about the symmetries. In this talk, I will discuss the equivalence algorithm for teleparallel gravity, which provides a set of invariants that uniquely characterizes (locally) a teleparallel gravity solution, and use this set of invariants to determine the group of symmetries for the space.

- November 1, 2019
- !!! Miniworkshop on Friday - 13:10 !!!
- Exact spacetimes in the Robinson-Trautman and Kundt classes
*Robert Švarc*- ÚTF
- November 1, 2019
- !!! Miniworkshop on Friday - 14:00 !!!
- Dynamical thin-shell and bridge-type wormholes and their asymptotics
*Otakar Svítek*- ÚTF
- November 1, 2019
- !!! Miniworkshop on Friday - 14:50 !!!
- Gravitational-wave packets: Rotation of inertial frames and formation of horizons
*Tomáš Ledvinka*- ÚTF
- November 5, 2019
- TBA
*Dr. Anslyn John*- Department of Mathematics, Rhodes University, Makhanda, Eastern Cape, South Africa
- November 26, 2019
- A gravitational collapse singularity theorem that improves Penrose's
*Prof. Ettore Minguzzi*- Department of Mathematics and Informatics "U. Dini", University of Florence
TBD

- 2019: spring
- 2018: spring, fall
- 2017: spring, fall
- 2016: spring, fall
- 2015: spring, fall
- 2014: spring, fall
- 2013: spring, fall
- 2012: spring, fall
- 2011: spring, fall
- 2010: spring, fall
- 2009: spring, fall
- 2008: spring, fall
- 2007: spring, fall
- 2006: spring, fall
- 2005: spring, fall
- 2004: spring, fall
- 2003: spring, fall
- 2002: spring, fall
- 2001: spring, fall
- 2000: spring, fall
- 1999: spring, fall
- 1998: spring, fall
- 1997: fall

*Jiří Bičák*
*Oldřich Semerák*

© October 11, 2019; Oldřich Semerák

© October 14, 2019; generated by application