Editorial to the Special Issue "Universe: Feature Papers 2023—Cosmology".

The editorial discusses recent observational data indicating that the cosmic expansion is accelerating, with dark energy and dark matter comprising a significant portion of the universe's energy density. Various telescopes and satellites are expected to provide further insights into modern cosmology. The text also explores different theories to explain the accelerated expansion, including dark energy and extended theories of gravitation. Additionally, the editorial highlights important subjects in modern cosmology, such as physics in the early universe, dark matter, and gravitational waves. [Extracted from the article]