Absorption of Gravitons and Photon Luminosities of Interstellar/Intergalactic Hydrogen Atoms

Abstract

We compute the emission and absorption rates of gravitons by hydrogen atoms. The absorption rate of gravitons is proportional to the number of hydrogen atoms and to the graviton luminosity. The number of hydrogen atoms in interstellar/intergalactic media can be large while the graviton luminosity of Sun, or a typical star, is in the eV to keV range that well overlaps with the resonance frequencies of the hydrogen atoms. Currently, the observational knowledge of the graviton luminosity in different regions of the Universe is limited, and here we will consider its value as unknown quantity that should be determined by independent astrophysical observations. We suggest measuring the ratio of the photon luminosities from interstellar/intergalactic hydrogen atoms that can provide information concerning the luminosity of gravitons in different regions of space. This ratio maximally exposes the fundamental physical nature of photons and gravitons - their helicity, which is one for the photons and two for the gravitons. The ratio is sensitive to any sources of gravitational radiation and provide a possible method for measuring their radiation intensities.

Comments: 28 pages, 5 figures, extended version, appendixes and references added