Stellar Basins of Gravitationally Bound Particles

  • Sept. 15, 2021, 4:00 pm US/Central
  • Ken Van Tilburg, New York University
  • Dan Hooper

Explore the consequences of a newly identified physical phenomenon: volumetric stellar emission into gravitationally bound orbits of weakly coupled particles such as axions, moduli, hidden photons, and fermions. While only a tiny fraction of the instantaneous luminosity of a star (the vast majority of the emission is into relativistic modes), the continual injection of these particles into a small part of phase space causes them to accumulate over astrophysically long time scales, forming what I call a “stellar basin”, in analogy with the geologic kind. The energy density of the Solar basin can surpass that of the relativistic Solar flux at Earth’s location after only a million years, for a sufficiently long-lived particle produced through an emission process whose matrix elements are unsuppressed at low momentum. This observation has immediate and striking consequences for direct detection experiments—including new limits on axion and hidden-photon parameter space independent of dark matter assumptions. I will discuss ongoing N-body simulations of the Solar basin, and preliminary results on indirect detection of basin particles around the Sun and other stars.


Please contact Justine Dunn at the day of the colloquium for zoom link. Because of security reasons, this can only be given the day of.