Talks and presentations

Searching the Cosmos: Ripples from Avant-Garde Cosmological Probes

December 07, 2020

Contributed Talk, alpha-Cen 2020 Annual Meeting, online conference, Beijing, China

I will give a brief overview of my research in the field of cosmology. In particular, I will talk very briefly about my research in Primordial Black Holes as dark matter candidates. Furthermore, I will talk about mu current research program on the thermal fossils from hydrogen reionization, and how their ripples from 12.8 billion years ago can help us learn more about how the Universe transitions from mainly neutral to highly ionized. In addition, I will mention the interesting open questions that require further investigation.

Lyman-alpha forest power spectrum as an emerging window into the epoch of reionization and cosmic dawn

November 01, 2020

Contributed Talk, Guo Shoujing Meeting, Zhuhai, Guangdong, China

During cosmic reionization, the IGM is heated by ultraviolet photons sourced primarily by the first stars and galaxies. This extreme heating leaves an imprint in the IGM via disrupting the neutral gas with the injection of thermal energy. The thermal relics, i.e. the disruption to the temperature-density evolution of the IGM due to this imprint, has been recently shown to survive to lower redshifts than previously thought (z~2). In this talk, I will demonstrate that these thermal relics depend on the astrophysics of reionization, thus they can, theoretically, be used to distinguish between different reionization histories. In the second part of the talk, I will show how these thermal relics in the Lyman-alpha forest power spectrum — currently a broadband systematic effect for the Lyman-alpha community —could potentially become a novel window into the epoch of reionization.

Lyman-alpha forest power spectrum as an emerging window into the epoch of reionization and cosmic dawn

July 06, 2020

Recorded Talk, Sazerac, online conference, Beijing, China

The memory of reionization in the Lya forest was recently shown to survive to lower redshifts than previously thought (z~2). This unconventional result originated from carefully tracking the small-scale structure to below jean mass prior to reionization with high-resolution simulations. As a result, one is able to track the HEMD (High-Entropy, Mean-Density) gas in mini-voids, which takes cosmological timescales to relax into the usual-temperature density relation of the IGM. Here, I will show how the memory of inhomogeneous reionization in the Lya forest power spectra — currently a broadband systematic effect for the Lya forest community- could potentially become a window into the Epoch of Reionization.