Hélène Courtois

Hélène (Di Nella) Courtois (born 1970) is a French astrophysicist specialising in cosmography. She is a professor at the University of Lyon 1 and has been a chevalier of the Ordre des Palmes Académiques since 2015.

As the director of a research team at the Lyon Institut de Physique des 2 Infinis (IP2I)—formerly the Institute of Nuclear Physics (IPNL)—and co-director of two international teams (Cosmic Flows and CLUES), she is best known for her investigations into the dynamic cosmography of the Universe. Her work has concentrated on the distribution of matter in the large-scale structure of the Universe. In 2006, she participated in the confirmation of the acceleration in the expansion of the Universe via the study of supernovae. In 2014, she proposed a redefinition of the notion of galactic superclusters, and identified the Laniakea Supercluster, an agglomeration that is bigger than the Virgo Supercluster by a factor of 100. In 2017, she showed that cosmic voids produce a repulsive effect resulting in galactic displacements; this may also explain the cold spot in the cosmic microwave background.