Modelling formation and evolution of globular clusters (GCs)
I update the GC formation model developed by Choksi & Gnedin (2019) by adding positional and kinematic information to the modeled GCs.

Giant molecular clouds (GMCs) with different initial density profiles
Together with Hui Li and Mark Vogelsberger, I perform a suite of simulations to investigate the effects of initial density profiles on the evolution of star clusters in GMCs. We find that the uniform profile follows a "hierarchical" cluster formation mode, while the steep power-law profiles show an "accretion" dominated mode. These two cluster formation modes lead to different proprieties of the most massive clusters in GMCs. See our first paper (Chen, Li, and Vogelsberger 2021) for details.

Projection of hierarchical cluster formation mode Projection of concentrated cluster formation mode

"Hierarchical" (left) and "accretion" (right) modes for cluster formation.


Pre-burst stage of gamma-ray bursts (GRBs)
Based on the cosmic light speed variation, I found a novel pre-burst stage for GRBs. I also employed a primary clustering method of machine learning to classify this stage with the data from the Fermi telescope. The work was completed in late 2019 but was accepted for publication in 2021 due to the COVID-19 pandemic (see, Chen and Ma 2021).

Two classifications of GRB photons

Two classifications of GRB photons. Classification A distinguishes pre-burst from main-burst.


ybchen (at)

323 West Hall, 1085 S. University, Ann Arbor, MI 48109-1107, USA


© 2020-2022 Bill Chen.
Last Modified in May 2022.