# Current seminars

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

Location (unless indicated otherwise): Währinger Str. 17

- Seminarraum A on the 2nd floor for **standard seminars**, and

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

The Mathematical Physics Seminars take place on Tuesdays at 13.45.

The Particle Physics Seminars take place on Tuesdays at 16.15.

- Wednesday,
**July 24th, 12:00**, lunch seminar

Jeremie Joudioux (AEI Potsdam):*Gravitational spin Hall effect for Maxwell fields*

Abstract: It is well known that photons, as particles, follow null geodesics in General Relativity. The corresponding wave dynamic is modelled by the Maxwell equations. The actual motion of the photon can be recovered, at least locally, by considering high-frequency solutions to the Maxwell equations. Nonetheless, it is well-known that the dynamics of wave packets can differ sensibly from the motion of the actual particles. One of this effect, known as the spin Hall effect, has been described for Maxwell equations propagating in a medium and observed mid-00. This can be explained by the spin degree of freedom of the particle interacting with the medium in which it propagates. In this collaboration, we propose to extend this notion of spin Hall effect to Maxwell field propagating on a curved background. The effective equation of motion describing the evolution of the wave packet can be compared with the equations of motions of spinning particles in General Relativity. We are in particular trying to develop a covariant approach to the construction of a WKB Ansatz for Maxwell field on curved backgrounds.

This is a collaboration with L. Andersson (AEI), M. Oancea (AEI), C. Paganini (Monash), I. Dodin (Princeton Plasma Physics Laboratory), and D. Ruiz (Sandia Laboratory).

- WS 2019:

Artur Alho (Lisbon): Spherically symmetric steady states of Newtonian self-gravitating elastic matter

Abstract: In this talk I will introduce a new definition of spherically symmetric elastic body in Newtonian gravity. Using this new definition it is possible to introduce Milne-type homology invariant variables which transform the field equations into an autonomous system of nonlinear differential equations. By employing dynamical systems methods I will finally discuss the existence of static balls for a wide variety of constitutive equations, including Seth, Signorini, Saint Venant-Kirchhoff, Hadamard, and John’s harmonic materials.