Seminarium Teorii Względności i Grawitacji

It is widely known that, near spacelike singularities, most worldlines would undergo the so-called Belinski-Khalatnikov-Lifshitz (BKL) singularity dynamics, which is an infinite sequence of Kasner saddle states connected by Taub transitions.Some worldlines however would undergo highly inhomogeneous spike dynamics, which is an infinite sequence of Kasner saddle states connected by spike transitions.I will describe these dynamics using the Hubble-normalised orthonormal frame formulation of Einstein's field equations, which is very useful for spatially homogeneous models (we get a system of ordinary differential equations), and also suitable for inhomogeneous models.My contributions in this area are the discovery of the exact solutions which describe the spike transitions, and the development of a numerical zooming technique specially designed for spike simulations.I will illustrate the spike transitions with snapshots of the Hubble-normalised state space trajectories, and point out interesting features.Zoom Meeting ID: 814 7211 6408 Passcode: 795365