Adam G. Riess

Adam Guy Riess is an American astrophysicist at The Johns Hopkins University and the Space Telescope Science Institute and is known for his research in using supernovae as cosmological probes. Riess shared both the 2006 Shaw Prize in Astronomy and the 2011 Nobel Prize in Physics with Saul Perlmutter and Brian P. Schmidt for providing evidence that the expansion of the universe is accelerating.Riess was a Miller Fellow at the University of California, Berkeley before moving on to the Space Telescope Science Institute in 1999. He took up his current position at Johns Hopkins University in 2005.

Riess jointly led the study with Brian Schmidt in 1998 for the High-Z Supernova Search Team which first reported evidence that the Universe's expansion rate is now accelerating though monitoring of Type 1a Supernova. The team's observations were contrary to the current theory that the expansion of the universe was slowing down; instead, by monitoring the color shifts in the light from the supernova from Earth, they discovered that these billion-year old nova were still accelerating. This result was also found nearly simultaneously by the Supernova Cosmology Project, led by Saul Perlmutter. The corroborating evidence between the two competing studies led to the acceptance of the accelerating universe theory, and initiated new research to understand the nature of the universe, such as the existence of dark matter. The discovery of the accelerating universe was named 'Breakthrough of the Year' by Science Magazine in 1998, and Riess was jointly awarded the 2011 Nobel Prize in Physics along with Schmidt and Perlmutter for their groundbreaking work.

Riess leads the Higher-Z SN Search program which uses the Hubble Space Telescope to discover the most distant supernovae yet uncovered by humankind. His team has traced the Universe's expansion back more than 10 billion light years. The key finding has been the detection of an early phase of decelerating expansion causing the most distant supernovae to look relatively brighter and thus disfavoring significant astrophysical dimming of supernovae. This result thus confirms the dark energy-dark matter model as perceived from supernovae.

Saul Perlmutter, Riess, and Brian P. Schmidt being awarded the 2006 Shaw Prize in Astronomy. The trio would later be awarded the 2011 Nobel Prize in Physics.

Riess received the Astronomical Society of the Pacific's Trumpler Award in 1999 and Harvard University's Bok Prize in 2001. He won the American Astronomical Society's Helen B. Warner Prize in 2003 and the Raymond and Beverly Sackler Prize in 2004 for the discovery of cosmic acceleration. In 2006, he shared the $1 million Shaw Prize in Astronomy with Saul Perlmutter and Brian P. Schmidt for contributions to the discovery of the acceleration of the universe.

Schmidt and all the members of the High-Z Team shared the 2007 Gruber Cosmology Prize, a $500,000 award, with the Supernova Cosmology Project (the set defined by the co-authors of Perlmutter et al. 1999) for their discovery of the accelerating expansion of the universe. Riess was the winner of MacArthur "Genius" Grant in 2008. He was also elected in 2009 to the National Academy of Sciences. Along with Perlmutter and Schmidt, he was awarded the 2011 Nobel Prize in Physics for his contributions to the discovery of the acceleration of the expansion of the universe.