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 luminosity distance, the Einstein field equation, Stephen Hawking's contributions, and the cosmological principle, among other cosmological concepts.
Covers gravitational lensing in astrophysics, including deflection angle, Einstein radius, lens solution, and its application to galaxies and the universe.
