skip to content


I am an Associate Professor working in the field of cosmology, the study of how the universe began and evolved into what we see today. I am also Director of Graduate Studies for the Department.

My research , and that of the students working with me, focuses on cosmological theories and how we can constrain them using observations such as the cosmic microwave background "CMB" (radiation emitted at the earliest, directly-observable time in the universe's history), and large scale structure data (galaxies and clusters of galaxies). My work focuses on improving our understanding of the nature of dark energy, the mysterious quantity responsible for the accelerated expansion of the universe, and dark matter, and how can we use observations to distinguish between competing theories. I'm also interested in the application of high energy theories to understanding the properties of cosmic inflation in the first moments after the universe was conceived. Inflation is believed to be the process that seeded the large scale structure that we observe today,.

I am actively involved in three upcoming large scale structure surveys: DESI, Euclid and LSST. I am the Science Analysis Coordinator for the LSST Dark Energy Science Collaboration. I am a member of the NASA Euclid Science Team, and am co-leading the work effort on "Testing Gravity" in the Euclid collaboration. In the DESI collaboration, I'm co-leading the "Small scale clustering, clusters and combined probes" work group.

These surveys will create meticulously detailed maps of the images or spectral properties of galaxies and galaxy clusters over volumes of space billions of lightyears across. Extracting the cosmological information from these surveys is a challenging enterprise, requiring computational infrastructure and algorithms to manage the massive datasets (e.g. LSST will create datasets of hundreds of TBs each night, and tens of petabytes over its lifetime).

A particular interest I have is on the cosmological and astrophysical information we can extract when datasets using distinct techniques and instruments are combined and cross-correlated. LSST, Euclid and DESI are highly complementary in both redshift coverage and in providing distinct maps of the properties of matter and gravity in the cosmos. In combination with each other, and with other surveys, at CMB and X-ray frequencies for example, they will help us understand dark energy, dark matter and inflation in unprecedented detail.



Rachel Bean
612 Space Sciences Bldg
Department of Astronomy
Cornell University
Ithaca, NY 14853
607 254 4920