Mon 22 Jan 14:00: Scattering towards the singularity in Kasner spacetimes
The Kasner spacetimes are solutions to Einstein’s equations that play a decisive role in the study of spacelike singularities in GR. In this talk, we study two model hyperbolic systems in Kasner spacetimes, namely the scalar wave equation and the linearized Einstein(-scalar field) system, whose solutions have certain quantitative blow-up asymptotics near the singularity of Kasner. We present recent results deriving a sharp correspondence between Cauchy data and asymptotic data at the singularity, which reveals interesting phenomena regarding gains and losses of regularity.
- Speaker: Warren Li, Princeton University
- Monday 22 January 2024, 14:00-15:00
- Venue: MR13.
- Series: Partial Differential Equations seminar; organiser: Amelie Justine Loher.
Mon 22 Jan 14:00: Title to be confirmed
Abstract not available
- Speaker: Warren Li, Princeton University
- Monday 22 January 2024, 14:00-15:00
- Venue: MR15.
- Series: Partial Differential Equations seminar; organiser: Amelie Justine Loher.
Wed 21 Feb 14:15: TBD
TBD
- Speaker: Marta Benozzo, UCL
- Wednesday 21 February 2024, 14:15-15:15
- Venue: CMS MR13.
- Series: Algebraic Geometry Seminar; organiser: Holly Krieger.
Wed 31 Jan 16:00: 2-torsion rational homology spheres and SL(2,C)-representations
We use instanton gauge theory to prove that if Y is a closed, orientable 3-manifold such that H_1(Y;Z) is nontrivial and 2-torsion, and if Y is neither an r-fold connected sum of RP3s for some r>=1, then there is an irreducible representation of the fundamental group of Y in SL(2,C). This solves a conjecture of Przytycki (Kirby problem 1.92(F)) on torsion in the Kauffman Skein module of reducible 3-manifolds, unless every summand but one is RP3 . This is joint work with Sudipta Ghosh and Steven Sivek.
- Speaker: Raphael Zentner (Durham)
- Wednesday 31 January 2024, 16:00-17:00
- Venue: MR13.
- Series: Differential Geometry and Topology Seminar; organiser: Oscar Randal-Williams.