Quantum gravity effects on fermionic dark matter and gravitational waves

We explore the phenomenological consequences of breaking discrete global symmetries inquantum gravity (QG). We extend a previous scenario where discrete global symmetries areresponsible for scalar dark matter (DM) and domain walls (DWs), to the case of fermionic DM,considered as a feebly interacting massive particle, which achieves the correct DM relic densityvia the freeze-in mechanism. Due to the mixing between DM and the standard model neutrinos,various indirect DM detection methods can be employed to constrain the QG scale, the scale offreeze-in, and the reheating temperature simultaneously. Since such QG symmetry breaking leads toDW annihilation, this may generate the characteristic gravitational wave background, and henceexplain the recent observations of the gravitational wave spectrum by pulsar timing arrays. Thiswork therefore highlights a tantalizing possibility of probing the effective scale of QGfrom observations.

Note:

13 pages, 5 figures. Accepted for publication in JCAP. Corrected a typo in one of the speaker's names

Cosmic strings
domain walls
monopoles
dark matter theory
gravitational waves / sources
quantum gravity phenomenology
fermion: dark matter
symmetry: global
dark matter: relic density
gravitational radiation: background

References(0)

Figures(5)

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