Beijing Institute of Mathematical Sciences and Applications

Jahed Abedi , Dey Dipanjan , Puskar Mondal , Alejandro Torres-Orjuela

Konstantinos Tzanavaris

Wednesday, June 3, 2026 2:30 PM - 3:30 PM

A3-2-301

Zoom 928 682 9093 (BIMSA)

One of the central problems in cosmology in the determination of the initial condition at the Big Bang. In this talk, I will present a general methodology for assigning boundary conditions to singularities by treating the initial singularity as a free boundary. It will be shown that conformally regular cosmologies sourced by sub-stiff fluids are solutions to the free boundary problem, whereas Kasner-like and BKL geometries are not. In particular, it will be shown that linearised perturbations around FLRW are solutions to the free boundary problem if and only if they obey time-reflecting initial conditions at the Bang, thereby giving a variational derivation of CPT-symmetric cosmologies. Finally, it will be shown how this methodology can be applied to null boundaries, giving alternatives to the classical solutions describing black holes.

I’m currently a postdoc at the Max Planck Institute (AEI), in Hannover, under the supervision of Bruce Allen. My research interests lie in mathematical physics, with emphasis on General Relativity and gravity. After getting my BSc in Physics at the University of Patras in 2020, I went in 2021 to the University of Edinburgh to study under Neil Turok, getting my PhD in September 2025. The same month, I started my postdoc at the AEI.