BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Ken Van Tilburg (NYU/Flatiron CCA) DTSTART:20210406T170000Z DTEND:20210406T180000Z DTSTAMP:20260423T004731Z UID:nhetc/8 DESCRIPTION:Title: St ellar Basins of Gravitationally Bound Particles\nby Ken Van Tilburg (N YU/Flatiron CCA) as part of NHETC Seminar\n\n\nAbstract\nI will describe a nd explore the consequences of a peculiar physical phenomenon: volumetric stellar emission into gravitationally bound orbits of weakly coupled parti cles such as axions\, moduli\, hidden photons\, and neutrinos. While only a tiny fraction of the instantaneous luminosity of a star (the vast majori ty of the emission is into relativistic modes)\, the continual injection o f these particles into a small part of phase space causes them to accumula te over astrophysically long time scales\, forming what I call a "stellar basin"\, in analogy with the geologic kind. The energy density of the Sola r basin can surpass that of the relativistic Solar flux at Earth's locatio n after only a million years\, for any sufficiently long-lived particle pr oduced 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 hidde n-photon parameter space independent of dark matter assumptions---and open s up prospects for indirect detection of weakly interacting particles arou nd stars. [Based on https://arxiv.org/abs/2006.12431 and https://arxiv.org /abs/2008.08594\, and ongoing work.]\n LOCATION:https://researchseminars.org/talk/nhetc/8/ END:VEVENT END:VCALENDAR