The Role of Galaxy Surveys in Mapping Cosmic Evolution

Abstract

Galaxy redshift surveys are one of the main ways of knowing how the universe as evolved. These surveys show how the matter forms a large-scale cosmic web of filaments, galaxy clusters and empty ‘voids. Dark matter can be seen to influence this pattern, which can be seen to still have the imprint of an early universe. A key pattern, the baryon acoustic oscillation scale, acts as a lengthtime tracker for tracking how the universe’s expansion has changed over time. In studying how galaxy clustering evolves with distance, surveys show that structure growth has slowed as dark energy began to dominate becoming a greater proportion of the total mass-energy content in the universe, causing the accelerated expansion of the universe. More recently, multi-messenger astronomy featuring gravitational waves, gamma rays and neutrinos have allowed astronomers to observe more cosmic events leading to greater evidence. Galaxy surveys provide some of the strongest evidence for the current model of the universe’s evolution from the Big Bang to the present day.