Richard S. Ellis

Richard S. Ellis is a Visiting Associate Professor at the California Institute of Technology's Division of Physics, Mathematics, and Astronomy. He holds a B.Sc. from University College London (1971) and a D.Phil. from the University of Oxford (1974), with an honorary D.Sc. from Durham University. His research focuses on observational cosmology, galaxy formation, gravitational lensing, and the early universe. Ellis has been instrumental in studies of Type Ia supernovae, contributing to the discovery of cosmic acceleration recognized by the 2011 Nobel Prize in Physics (awarded to the Supernova Cosmology Project).

Ellis has held leadership roles, including Director of Palomar Observatory and Caltech Optical Observatories. His current projects include the Prime Focus Spectrograph for the Subaru Telescope and the Wide Field Spectroscopic Telescope. He is affiliated with University College London as the Principal Investigator of the First Light team. Ellis has supervised 27 graduate students, many of whom continue in academic research.

His research explores gravitational lensing's role in cosmology, distant supernovae validation, large-scale structure mapping, and the study of early galaxies' role in cosmic reionization using JWST, Hubble, and other instruments. Ellis serves on committees for the Kavli Institute for Astronomy and Astrophysics, the ORIGINS Cluster, and the Royal Society.