Cosmological constraints from the Dark Energy Survey

Event Date:
2026-03-09T16:00:00
2026-03-09T17:00:00
Event Location:
HENN 318
Speaker:
Gary Bernstein, University of Pennsylvania
Related Upcoming Events:
Astronomy Colloquia
Intended Audience:
Everyone
Local Contact:

Allison Man (aman@phas.ubc.ca) and Brett Gladman (gladman@astro.ubc.ca)

All are welcome to this event!

Event Information:

Abstract:

The Dark Energy Survey (DES) imaged 1/8 of the full sky 10 times in each of 5 optical/NIR filters over the course of 6 years.  I will describe the survey, and the results of the recently completed primary cosmological analysis using the weak gravitational lensing and clustering measured from  ~150 million galaxies.  These measurements, combined with the Hubble diagram derived from ~1600 DES Type Ia supernovae, and other state-of-the-art optical/NIR surveys, offer the most stringent tests to date of whether the low-redshift universe we see could have evolved from its early state, as observed via the cosmic microwave background, under the baseline “LCDM” cosmological model.  I will describe how advances in methodology, as well as larger surveys, should yield more-stringent tests in the coming few years.

Bio:

Gary Bernstein’s research is focused on the use of gravitational lensing—the deflection of light by gravity as predicted by general relativity. His current work consists of large astronomical survey projects from space and ground that will use this lensing effect to measure as-yet-unexplained dark matter and dark energy. His past projects have included surveys of the solar system beyond Neptune and construction of one of the first mosaic CCD cameras to be placed on a large telescope, which was used to measure many of the high-redshift supernovae that provided early evidence of the accelerating universe.

The recipient of a CAREER Faculty Award from the National Science Foundation, Bernstein received his doctorate from the University of California, Berkeley, and his bachelor’s degree in physics from Princeton University. He taught at the University of Michigan before joining the Penn faculty in 2002. Bernstein is co-creator of the popular Penn physics course Energy, Oil, and Global Warming.

Resources:

Add to Calendar 2026-03-09T16:00:00 2026-03-09T17:00:00 Cosmological constraints from the Dark Energy Survey Event Information: Abstract: The Dark Energy Survey (DES) imaged 1/8 of the full sky 10 times in each of 5 optical/NIR filters over the course of 6 years.  I will describe the survey, and the results of the recently completed primary cosmological analysis using the weak gravitational lensing and clustering measured from  ~150 million galaxies.  These measurements, combined with the Hubble diagram derived from ~1600 DES Type Ia supernovae, and other state-of-the-art optical/NIR surveys, offer the most stringent tests to date of whether the low-redshift universe we see could have evolved from its early state, as observed via the cosmic microwave background, under the baseline “LCDM” cosmological model.  I will describe how advances in methodology, as well as larger surveys, should yield more-stringent tests in the coming few years. Bio: Gary Bernstein’s research is focused on the use of gravitational lensing—the deflection of light by gravity as predicted by general relativity. His current work consists of large astronomical survey projects from space and ground that will use this lensing effect to measure as-yet-unexplained dark matter and dark energy. His past projects have included surveys of the solar system beyond Neptune and construction of one of the first mosaic CCD cameras to be placed on a large telescope, which was used to measure many of the high-redshift supernovae that provided early evidence of the accelerating universe. The recipient of a CAREER Faculty Award from the National Science Foundation, Bernstein received his doctorate from the University of California, Berkeley, and his bachelor’s degree in physics from Princeton University. He taught at the University of Michigan before joining the Penn faculty in 2002. Bernstein is co-creator of the popular Penn physics course Energy, Oil, and Global Warming. Resources: View Gary's University of Pennsylvania faculty page and personal website Read UPenn article "Gary Bernstein Honored for Extraordinary Achievement and Service" Watch his video on the evidence for Dark Matter: Gary Bernstein - The evidence for Dark Matter  Event Location: HENN 318