ABSTRACT
The standard LCDM model seems to fail to reconcile the discrepancy of the H0 measurements between the early and late Universe. This H0 tension has become an increasingly mystery in the cosmology community. Moreover, the galaxy survey measurement of S8 value, namely the amplitude of matter density fluctuation, is smaller than the value inferred from CMB assuming LCDM, although with a less significance compared to the H0 tension. Despite of the possibility of unknown systematic errors in the measurements, one may expect the potential of discovering new physics behind these tensions.
In this talk, I will briefly review the possible theoretical solutions to these two cosmological tensions. I will mainly focus on the Early Dark Energy-like model as a H0 tension solution and its interaction with dark matter, exploring the ability of this interaction to explain the EDE coincidence problem and simultaneously solve the S8 tension. I will also talk about a late time Dark Energy Tracking Growth as a solution to the S8 tension. The future paths will be discussed.
BIO
Dr. Meng-Xiang Lin is currently a Postdoctoral Fellow of Center of Particle Cosmology at University of Pennsylvania starting from 2022. Before going to UPenn, he finished his undergrad at PKU in 2015, and received his PhD at University of Chicago in 2022. He is generally interested in various topics of theoretical cosmology. Specifically, his works mainly on seeking theoretical solutions to the cosmological tensions, and using gravitational waves to test fundamental physics. You can find more information in his personal website: https://m-x-lin.github.io/index.html.
