Carnegie Mellon University
June 24, 2019

Carnegie Mellon Physicist Rachel Mandelbaum Named 2019 Simons Investigator

By Jocelyn Duffy

Jocelyn Duffy
Carnegie Mellon University physicist Rachel Mandelbaum has been named a 2019 Simons Investigator by the Simons Foundation.

The Simons Investigator program provides research support to outstanding scientists, enabling them to undertake the long-term study of fundamental questions. Mandelbaum is the first Carnegie Mellon researcher to be selected for this prestigious program.

"I am honored to have been named a Simons Investigator. This source of support will be of great value to my research group during the next five years, which will be particularly exciting times as we explore many questions in cosmology with new datasets," Mandelbaum said.

Mandelbaum, a professor in the Department of Physics and a member of the McWilliams Center for Cosmology, seeks to better understand the universe - how it started and how it came to be as it is today. Specifically, Mandelbaum studies weak gravitational lensing, which looks at distortions in images of distant galaxies obtained by telescopes.

When light from far-away galaxies travels towards Earth - and the lenses of terrestrial telescopes - it passes by other objects in the universe. The masses of these objects bend the path taken by light as it travels past, resulting in distorted images. Mandelbaum studies the slightest of these distortions, which contain valuable information about how matter was distributed in the early universe and how matter evolved to the large-scale structure we see today. It also holds clues to the nature of dark matter and dark energy.

"Rachel is a leader in the field of gravitational lensing, and her work is paving the paving for exciting discoveries over the coming decade. We are thrilled that the Simons Foundation has acknowledged the importance of her work," said Scott Dodelson, professor and head of the Department of Physics at Carnegie Mellon.

Mandelbaum is particularly known for her work that pairs cosmological observations with computer science, statistics and data science. To accurately measure the tiny weak lensing distortions, researchers must collect data from tens of millions of galaxies. They also need to correct for other causes of blurring caused by telescopes or the atmosphere. Mandelbaum creates algorithms that take sources of observational and theoretical uncertainty into account to learn about how galaxies relate to their dark matter halos and to measure cosmological parameters from large telescope datasets.

These algorithms are used by leading astronomical surveys, including the Hyper Suprime-Cam Survey and the upcoming Large Synoptic Survey Telescope (LSST), Euclid and WFIRST projects.

Mandelbaum has held a number of leadership roles and won numerous awards in physics and cosmology. She was recently elected the spokesperson for the LSST's Dark Energy Science Collaboration (DESC) and previously served as the DESC analysis coordinator and co-leader of the weak lensing working group. She received the Annie Jump Cannon Prize from the American Astronomical Society, a Department of Energy Early Career Award and an Alfred P. Sloan Fellowship.