Physical cosmology
Videos
Physical cosmology is a branch of physics concerned with modeling the universe based on the laws of physics. A cosmological model provides a mathematical description of the largest-scale structures an
An example of a gravitational lens found in the DESI Legacy Surveys data. There are four sets of lensed images in DESI-090.9854-35.9683, corresponding to four distinct background galaxies—from the outermost giant red arc to the innermost bright blue arc, arranged in four concentric circles. All of them are gravitationally warped—or lensed—by the orange galaxy at the very center. Dark matter is expected to produce gravitational lensing also.
Reionization
Videos
In the fields of Big Bang theory and cosmology, reionization is the process that caused electrically neutral atoms in the primordial universe to reionize after the lapse of the "dark ages". Detecting
Phases of the reionization
Schematic timeline of the universe, depicting reionization's place in cosmic history.
Astronomers hope to use observations such as this 2018 Hubble Space Telescope image to answer the question of how the Universe was reionised.