Very wide stellar binaries as probes of fundamental physics

Prof. Julio Chanamé  – P. Universidad Católica de Chile

Our present standard model of gravity, General Relativity (and Newtonian gravity, in the appropriate limit), has been experimentally tested with success at various scales and regimes, from our daily life to phenomena ranging from the Solar System to double massive black holes that merge and produce gravitational waves. Yet in the limit of very low accelerations, tests have been harder to come up with. This is an unsatisfactory situation, given that the rotation curves of disk galaxies fall precisely within that regime, and application of the standard model leads inevitably to requiring the presence of dark matter. The orbital accelerations experienced by the components of very wide binaries (semimajor axes of a few thousand AUs) fall within this special regime of gravity. Not only that, but they do not present the ambiguities associated to the potential presence of any dark matter, thus offering us an important and rare opportunity to test gravity in the weak acceleration regime. I will discuss the present-day situation, including our latest results based on state-of-the-art observations from Gaia and ground-based facilities. I will also present how wide binaries in our Galaxy and beyond can inform us about the fundamental properties of dark matter, under the assumption that this elusive component of the universe actually exists.

Miércoles 14 de noviembre de 2018, 12:00 hrs, Sala Sergio del Campo
Facultad de Ciencias, Campus Curauma, PUCV