Gravitational remnants from cosmological domain walls

by Prof. Naoya Kitajima (Tohoku University, Japan)

Monday 26 May 2025, 15:00 → 16:00 Asia/Shanghai

Tsung-Dao Lee Institute/N6F-N600 - Lecture Room (Tsung-Dao Lee Institute)

Abstract:

Domain walls can be produced in the early universe accompanied by spontaneous breaking of discrete symmetry. To avoid the cosmological domain wall problem, they must be annihilated in the early universe, and this annihilation process can emit sizable amount of gravitational wave, which can be detected by gravitational wave observatories. 
In this seminar, I will discuss the gravitational wave emission from the domain wall network based on numerical lattice simulations and implications for future gravitational wave observations.
In addition, I also focus on the primordial black hole formation from domain walls. I will show my ongoing work on the dynamical black hole formation from the collapse of closed domain wall shells based on numerical relativity simulations.

Bio:

Naoya Kitajima has been an Assistant Professor at Tohoku University, Japan, since 2019. He obtained his PhD from the Institute for Cosmic Ray Research (ICRR) at the University of Tokyo in 2014. His research broadly covers particle cosmology, with a focus on light dark matter, primordial black holes, and domain walls, leveraging his strong expertise in numerical simulations.

Host: Prof. Yuichiro Nakai

Alternative online link：https://meeting.tencent.com/dm/WniLqnxwezBJ 

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