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SUMMARY:Axion Star Explosions - David Marsh (KCL)
DTSTART:20230530T120000Z
DTEND:20230530T130000Z
UID:TALK199015@talks.cam.ac.uk
CONTACT:Inigo Zubeldia
DESCRIPTION:Axion stars form in the centres of DM halos. If the axion is c
 oupled to electromagnetism\, then axion stars are unstable above a critica
 l mass\, and explode releasing low energy photons. Explosions are simulate
 d in full (3+1)d numerical General Relativity. For axion masses in the ran
 ge 1e-11 eV and couplings of order 1e-12 GeV^-1\, axion star instability i
 s predicted to happen in the first DM structures formed\, with masses of o
 rder 1 Msol at redshifts z~30. The rate of such explosions is computed fro
 m halo merger histories in standard cosmology. Axion star explosions lead 
 to enhanced DM decay during the dark ages\, which heats the intergalactic 
 medium. Constraints on anomalous heating from the CMB optical depth lead t
 o new and powerful constraints on axion parameter space. Future 21cm measu
 rements can provide complementary probes of axion parameter space to the D
 MRadio direct detection program.
LOCATION:CMS\, Pav. B\, CTC Common Room (B1.19) [Potter Room]
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