" This result, however, does not absolutely exclude detection of gravitons; one can imagine filling the solar system and beyond with tiny detectors. At this point, though, the possibilities go out of sight.
Before that point, we must address two other issues. The first is noise. Any detector needs to be shielded against background noise. Two serious noise sources are neutrinos and cosmic rays. The cross section for the interaction of neutrinos with matter is about 0−45cm2 , or at least twenty orders of magnitude greater than the gravito-electric cross section. In a typical white dwarf, neutrino emission exceeds photon emission, meaning that 1013−14 neutrinos are emitted for every graviton. Therefore, without shielding, one would expect 1033−34 neutrino events for every graviton event. A shield should be thicker than the mean-free-path for neutrinos, which for materials of ordinary density amounts to light years. Such a shield would collapse into a black hole. Unless one can find another way to discriminate against neutrinos, this appears to make detection of thermal gravitons impossible. In light of this result, we do not pursue shielding against cosmic rays, which would activate the detector material, inundating it with secondary particles. "
Can Gravitons Be Detected?
and Stephen Boughn
∗ Princeton University,
Princeton, NJ 08544 † Haverford College,
Haverford, PA 19041 LATEX-ed February 4, 2008http://arxiv.org/pdf/gr-qc/0601043v3.pdf