Xiaoyong Chu

Best Paper Award 2019

Xiaoyong Chu wird für sein Paper Velocity Dependence from Resonant Self-Interacting Dark Matter, veröffentlicht in PHYSICAL REVIEW LETTERS 122, 071103 (2019) ausgezeichnet.

The gravitational evidence for dark matter is well established, and deciphering its microphysical properties is one of the most actively pursued goals in fundamental physics. Despite an overwhelming positive body of evidence, cosmological measurements suggest that there exists an unexpected mass deficit in small dark matter halos that host dwarf and low-surface-brightness galaxies. This is not expected in any simple models of dark matter, but may rather indicate that dark matter is substantially self-interacting. On the other side, however, no such mass deficit is observed in much larger halos that host clusters of galaxies, putting a principal limit on the strength of such self-interaction, which is tighter than what is required for the small haloes.

Xiaoyong Chu and his collaborators solved this conundrum by proposing that the dark matter self-interaction strongly depends on velocity, through the presence of a resonance. Using a model-independent approach, they show that resonant self-interacting dark matter can naturally explain the observational data. Dark matter particles in small haloes generally have low, yet special velocities that make two-body collisions resonant, so that the corresponding cross section is significantly enhanced as compared to the cross section found in clusters of galaxies. This is a novel solution to the mass deficit problem, and thus opens up a new avenue for self-interacting dark matter model-building. At last, astrophysical observations with higher precision will be able to test this solution in the future.

Der Preisträger

Xiaoyong Chu war von 2005-2007 Forschungsassistent an der University of Science and Technology of China. Das Masterstudium im Fach Allgemeine Physik hat er 2009 an der Chalmers University of Technology, Schweden, abgeschlossen; 2013 dissertierte er im Fach Theoretische Physik an der Université Libre de Bruxelles, Belgien. Von 2013-2016 hatte Xiaoyong Chu eine Postdoc-Stelle am International Center for Theoretical Physics in Triest; seit 2016 ist Xiaoyong Chu Postdoc am Institut für Hochenergiephysik der ÖAW.