PI DESI Initiative

A force known as dark energy is driving the expansion of universe at an accelerated rate, but we don’t know what it is.

The Dark Energy Spectroscopic Instrument (DESI) will give scientists insights into this deep cosmological mystery.

By obtaining optical spectra for tens of millions of galaxies and quasars to generate a 3D map spanning the nearby universe to 11 billion light years, DESI will help answer the questions about dark energy, which represents roughly 68 percent of the energy content of the universe.

DESI officially began its five-year survey on May 17, 2021, but computational scientist Dustin Lang and research associate faculty Will Percival have been core members in the development and construction of DESI from its initial phases, more than a decade ago. They are both designated as “builders,” a status that acknowledges their significant contributions from the beginning.

Since then, postdoctoral researcher Alex Krolewski (appointed jointly between Perimeter and the University of Waterloo) has joined the DESI team,

Perimeter and the University of Waterloo are growing the team of faculty, postdoctoral fellows and graduate students working on DESI and associated projects.

DESI is mounted on the four-metre Mayall telescope at Kitt Peak National Observatory in Arizona. It is the product of an international collaboration that brings together more 450 researchers from more than 70 institutions around the world. The collaboration is led by Lawrence Berkeley National Laboratory and managed by the University of California for the U.S. Department of Energy’s Office of Science.

Besides shedding light on our understanding of dark energy, the DESI project is also useful to other cosmological quests that Perimeter scientists are involved in.

For example, Perimeter faculty member Kendrick Smith and his former PhD student Masoud Rafiei-Ravandi, who are part of the Canadian Hydrogen Intensity Mapping Experiment (CHIME) collaboration have also used the list of galaxies that DESI wants to observe — before the DESI observations happened! — and found a correlation between another cosmological mystery, fast radio bursts, and some of those galaxies.

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