This is a list of people who have made noteworthy contributions to cosmology (the study of the history and large-scale structure of the universe) and their cosmological achievements A Tom Abel (1970–) studied primordial star formation Roberto Abraham (1965–) studied the shapes of early galaxies Andreas Albrecht studied the formation of the early universe, cosmic structure, and dark energy Hannes Alfvén (1908–1995) theorized that galactic magnetic fields could be generated by plasma currents Ralph A. Alpher (1921–2007) argued that observed proportions of hydrogen and helium in the universe could be explained by the big bang model, predicted cosmic background radiation Aristarchus of Samos (310–230 BC) early proponent of heliocentrism Aristotle (circa 384–322 BC) posited a geocentric cosmology that was widely accepted for many centuries Aryabhata (476–550) described a geocentric model with slow and fast epicycles B Ja'far ibn Muhammad Abu Ma'shar al-Balkhi (787–886) conveyed Aristotle's theories from Persia to Europe James M. Bardeen (1939–2022) studied the mathematics of black holes and of vacua under general relativity John D. Barrow (1952–2020) popularized the anthropic cosmological principle Charles L. Bennett (1956–) studied the large-scale structure of the universe by mapping irregularities in microwave background radiation Orfeu Bertolami (1959–) studied the cosmological constant, inflation, dark energy-dark matter unification and interaction, alternative gravity theories Somnath Bharadwaj (1964–) studied large-scale structure formation James Binney (1950–) studied galactic dynamics and supernova disruption of galactic gasses Martin Bojowald (1973–) studied loop quantum gravity and established loop quantum cosmology Hermann Bondi (1919–2005) developed the steady-state model Mustapha Ishak Boushaki (1967–) physicist researcher on Cosmology Tycho Brahe (1546–1601) promoted a geo-heliocentric system of epicycles Robert Brandenberger (1956–) formulated the theory of string gas cosmology, with colleague Cumrun Vafa, and developed cosmological perturbation theory C Bernard J. Carr (1949–) promoted the anthropic principle, studied primordial black holes Sean M. Carroll (1966–) researched dark energy, general relativity, and spontaneous inflation Gennady V. Chibisov (1946–2008) origin of cosmological density perturbations from quantum fluctuations Peter Coles (1963–) modeled galactic clustering and authored several cosmology books C. B. Collins used the anthropic principle to solve the flatness problem Asantha Cooray (1973–) studied dark energy, halo models of large structure, and cosmic microwave radiation Nicolaus Copernicus (1473–1543) formulated a heliocentric cosmology D Paul Davies (1946–) developed a vacuum model that explains microwave background fluctuation, studies time's arrow, and has written many popular-press books Marc Davis (1947–) was lead astronomer of a survey of 50,000 high-redshift