Astrophysics & Particle Physics-APPC 2026

Galaxy Formation and Evolution is a core discipline of astrophysics that explores the way galaxies—the universe's building blocks—form, evolve, and change over billions of years. Galaxies come in a broad range of shapes, sizes, and types, ranging from spiral and elliptical galaxies to dwarfs and irregular galaxies, and each has a distinct evolutionary history influenced by star formation, gas dynamics, and galaxy interactions.Halos of dark matter are a central element in galaxy formation, which supply the gravitational framework for gas to accumulate and for star formation. As gas is cooled and condensed in these halos, it makes stars and stellar populations, constructing luminous objects we see.

As time passes in the universe, galaxies merge and interact, which can induce starbursts, reorganize morphology, and power the growth of supermassive black holes at galaxy centers.Galaxies viewed over a variety of redshifts enable astrophysicists to examine their history of formation and evolution. High-redshift galaxies give us a glimpse of the early universe, showing the processes that controlled galaxy assembly, star formation rates, and chemical enrichment. The proximal galaxies, on the other hand, give us detailed information about stellar populations, interstellar medium characteristics, and galactic dynamics.Galaxy evolution is also controlled by the cosmic web, large-scale structure of the universe created by networked filaments of dark matter and galaxies. Galaxy clusters and encounters with the intergalactic medium are among the key environmental influences that shape the history of galaxy evolution on a timescale of billions of years.Scientists can reconstruct the galaxy life cycle, from early formation in the early universe to the present-day complex galaxy structures, by combining observations, simulations, and theory. Study of galaxy evolution and formation not only deepens our knowledge of the universe but also offers vital information about the processes that shape the formation of stars, the distribution of matter, and the evolution of cosmic structures.