We investigate the possibility of using the cosmic gravitational focusing (CGF) to probe the minor light dark matter (DM) component whose mass is in the range of $(0.1 \sim 100)$\,eV. Being a purely gravitational effect, the CGF offers a mode-independent probe that is complementary to the existing ways such as Lyman-$\alpha$ and $\Delta N_{\rm eff}$. Such effect finally leads to a dipole...
Dark matter non-gravitational interactions can modify the evolution of cosmological perturbations in the early Universe, leaving observable imprints on large-scale structure. In this talk, I will introduce several studies that use weak-lensing measurements of the matter distribution—probing scales around k~1h/Mpc—to constrain dark matter interactions.
We explain the data of the DESI galaxy survey by using theoretical models of time-varying dark energy. Among such models, a quintessence field with the exponential potential is an attractive candidate for inducing time-varying dark energy. We analytically derive constraints on initial conditions that allow the kination epoch in the early Universe without conflicting with big bang...
