Physicists Propose Dark Matter Decay Search in 30% of Hubble Volume via Gamma Rays
Updated
Updated · ScienceAlert · Aug 3
Physicists Propose Dark Matter Decay Search in 30% of Hubble Volume via Gamma Rays
2 articles · Updated · ScienceAlert · Aug 3
Summary
A new Physical Review D study argues dark matter may be easier to spot indirectly if it decays into gravitons that later appear as gamma-ray photons.
The proposed signal relies on the Gertsenshtein effect: gravitons converting into photons while crossing weak, coherent magnetic fields in intergalactic filaments.
Those filaments could be prime targets because they span up to 30% of the present Hubble volume and extend across millions of light-years, giving conversion more distance to build up.
Researchers say the clearest evidence would be excess gamma-ray flux above Fermi Gamma-ray Space Telescope background levels, shifting the search from the Galactic center toward extragalactic space.
The approach adds only one new-physics assumption—that dark matter can decay to gravitons—and a proposed Advanced Particle-astrophysics Telescope could improve sensitivity by an order of magnitude.