.New results from the Dark Energy Survey use the largest ever sample of galaxies over an enormous piece of the sky to produce the most precise measurements of the universe’s composition and growth to date.  See SLAC press article here. This result featured the work of many current and former members of the GFC group, including Alex Amon, Matt Becker, Simon Birrer, Joe DeRose, Daniel Gruen, Elisabeth Krause, Jessie Muir, Eduardo Rozo, and Chun-Hao To.

Congrats to Ethan Nadler, who successfully defended his dissertation "Faint Galaxies and Small Halos: Probes of Galaxy Formation and Dark Matter"

One of the first students from the GFC group, Peter Behroozi (PhD 2012) has just been awarded tenure at the University of Arizona. Congrats to Peter for his many many accomplishments!

A new study shows that dark matter is about 1000 times less likely to bump into regular matter than previously expected.

From Symmetry magazine:
Scientists have narrowed down how strongly dark matter particles might interact with normal matter.
A team led by scientists from the US Department of Energy’s SLAC National Accelerator Laboratory and Stanford University found that, based on the number and distribution of small satellite galaxies seen orbiting our Milky Way, this interaction is at least a thousand times weaker than the strongest interaction allowed by previous astrophysical analyses.
“Improving our understanding of these interactions is important because it’s one of the factors that helps us determine what dark matter can and cannot be,” says Risa Wechsler, director of the SLAC/Stanford Kavli Institute for Particle Astrophysics and Cosmology and the study’s senior author.

Read full article here.

Risa Wechsler will participate in a conversation moderated by Brian Green at the World Science Festival on the search for the Universe's missing matter, May 29 at 8pm.