# The DIANA seminar

This seminar is an informal forum where members of the DIANA group meet to discuss topics of interest. We meet on a weekly basis. The programme for these meetings will be advertised below, and by email.

The the seminar takes place (at least for now) every Friday at 9.45 am in Seminarraum 7 (2nd floor) or at 10.15 in Seminarraum 11, as announced by email.

Anyone interested is welcome to attend.

## Summer term 2018

Date Speaker Title
02. Mar. 2018 Scheduling
09. Mar. 2018 Clemens Sämann
Lorentzian length spaces
AbstractWe introduce an analogue of the theory of length spaces into the setting of Lorentzian geometry and causality theory. The role of the metric is taken over by the time separation function, in terms of which all basic notions are formulated. In this way we recover many fundamental results in greater generality, while at the same time clarifying the minimal requirements for and the interdependence of the basic building blocks of the theory. A main focus of this work is the introduction of synthetic curvature bounds, akin to the theory of Alexandrov and CAT(k)-spaces, based on triangle comparison. Applications include Lorentzian manifolds with metrics of low regularity, closed cone structures, and certain approaches to quantum gravity. This is joint work with Michael Kunzinger. Preprint: https://arxiv.org/abs/1711.08990
16. Mar. 2018 Benedict Schinnerl
Master Defense - Length Structures and Geodesics on Riemannian Manifolds of Low Regularity
AbstractIn the thesis I dealt with Riemannian Manifolds of low Regularity. In particular applying results from metric Geometry/Theory of Length spaces. Further I dealt with several results/counterexamples concerning the regularity of geodesics for metrics below $C^{1,1}$ differentiability, as well as results on the exponential map for the borderline case of $C^{1,1}$ metrics. In the talk I will focus more on the geodesic aspect of the thesis, in particular focusing on the connection of geodesics and shortest paths as well as the regularity of shortest paths for metrics of low regularity.
23. Mar. 2018 Melanie Graf
t.b.a.
13. Apr. 2018 Stefan Palenta
Colliding plane waves
20. Apr. 2018 Roland Steinbauer
t.b.c.
27. Apr. 2018 Jiří Podolský
t.b.c.
04. May. 2018 Ondrej Hruska
t.b.c.
11. May. 2018 No seminar
18. May. 2018 Simon Reif
t.b.a.
25. May. 2018 t.b.a.
01. Jun. 2018 No seminar
08. Jun. 2018 Martin Gütlbauer
t.b.a.
15. Jun. 2018 Lorenzo Luperi Baglini
t.b.a.
22. Jun. 2018 Eduard Nigsch
t.b.a.
29. Jun. 2018 Michael Kunzinger
t.b.a.