Explores the expansion and Hubble law in astrophysics, covering the Hubble constant, cosmological redshift, critical density, and cosmic background radiation.
Explores the impact of COVID-19 on astronomy and the European Southern Observatory, delves into the Friedmann equations, and discusses the concept of dark energy.
Explores the classification and statistics of AGN, black holes, unified AGN model, variability, megamasers, orbital motion measurement, and time-delay cosmography.
Covers gravitational lensing in astrophysics, including deflection angle, Einstein radius, lens solution, and its application to galaxies and the universe.
