- Letter
- Open Access
Positron signal from the early Univere
Phys. Rev. D 111, L121304 – Published 27 June, 2025
DOI: https://doi.org/10.1103/897z-1k7m
Abstract
Bursts from the very early Universe may lead to a detectable signal via the production of positrons, whose annihilation gives an observable x-ray signal. Using the absorption parameters for the annihilation photons of 511 keV, it is found that observable photons would originate at a redshift around , resulting in soft x-rays of energy at present. Positrons are expected to be absent at these times or redshifts in the standard picture of the early universe. Detection of the x-rays would thus provide dramatic support for the hypothesis of the bursts, explosive events at very early times. We urge the search for such a signal.
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