, Währingerstrasse 17.

The Mathematical Physics Seminars take place on Tuesdays at 14.15.

The Particle Physics Seminars take place on Tuesdays at 16.15.

In addition to the Vienna
relativity seminars, the calendar above sometimes contains other events of interest
to members of the relativity group. The seminars of the Vienna relativity group
are listed below.

Unless explicitly stated otherwise, the regular (not-lunch) relativity seminars
take place in Room 218
**2nd floor **

- Monday,
**June 12**, pre-lunch seminar, 11:30, Paul Klinger (Vienna):*On continuous extensions of Lorentzian manifolds*

Abstract:
The study of low regularity extensions of Lorentzian manifolds was initiated by Sbierski's 2015 paper on the C^0 inextendibility of Schwarzschild. The interest in such extensions arises from their connection with the strong cosmic censorship conjecture, i.e. the question of whether maximal globally hyperbolic developments can be extended. Here, I will review Sbierski's proof, focusing on extensions across the r=0 singularity, and present some new results concerning C^0 extensions of
inhomogeneous spacetimes.

- Wednesday,
**June 14**, lunch seminar, 12:00, Sebastian Szybka (Cracow):*Linear perturbations of the near horizon extremal Kerr geometry*

Abstract: We show nonexistence of non-trivial solutions of the
linearised near-horizon equations
at the Kerr metric.

- Thursday,
**June 22**, l14:00, Manfried Faber (Vienna):*About the influence of gravitational waves on circular moving topological solitons with long range interaction*

Abstract:
The majority of physicists wants to quantize gravity. To unify gravity and particle physics there is another possibility, a geometrization of particle physics. We will present some ideas in this direction. I will give some short overview on a simple model of rotating Dreibeins. This model has four types of stable topological solitons differing in two topological quantum numbers which we identify with electric charge and spin. The vacuum has a two-dimensional degeneracy leading to two types of massless excitations, characterised by a topological quantum number which could have a physical equivalent in the photon number.
Inspired by the silicon oil drop experiment of Yves Couder we follow the idea that a subquantum medium could influence classical solitons on their path and lead to quantum mechanics. Under this point of view we investigate the influence of a gravitational wave background on particles in circular
motion.
Based on joint work with Martin Suda.

- Thursday,
**November 9**, 14:00, Ceslav Brukner (Vienna):*TBA*

Abstract:
TBA

Location (unless indicated otherwise): Währinger Str. 17

- Room 218
on the 2nd floor for **standard seminars**, and

- Common room, first floor, for **lunch seminars**.

Gravitational Physics

Faculty of Physics

University of Vienna

Boltzmanngasse 5

1090 Wien

T: +43-1-4277-51501

F: +43-1-4277-9515

Faculty of Physics

University of Vienna

Boltzmanngasse 5

1090 Wien

T: +43-1-4277-51501

F: +43-1-4277-9515