https://doi.org/10.1140/epjc/s10052-021-09263-w
Regular Article - Theoretical Physics
High frequency background gravitational waves from spontaneous emission of gravitons by hydrogen and helium
Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, 410081, Changsha, Hunan, China
Received:
29
June
2020
Accepted:
19
May
2021
Published online:
29
May
2021
A direct consequence of quantization of gravity would be the existence of gravitons. Therefore, spontaneous transition of an atom from an excited state to a lower-lying energy state accompanied with the emission of a graviton is expected. In this paper, we take the gravitons emitted by hydrogen and helium in the Universe after recombination as a possible source of high frequency background gravitational waves, and calculate the energy density spectrum. Explicit calculations show that the most prominent contribution comes from the 
transition of singly ionized helium 
, which gives a peak in frequency at 
Hz. Although the corresponding energy density is too small to be detected even with state-of-the-art technology today, we believe that the spontaneous emission of is a natural source of high frequency gravitational waves, since it is a direct consequence if we accept that the basic quantum principles we are already familiar with apply as well to a quantum theory of gravity.
© The Author(s) 2021
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Funded by SCOAP3
