Does Entropic Gravity Bound the Masses of the Photon and Graviton?

Abstract

If the information transfer between test particle and holographic screen in entropic gravity respects both the uncertainty principle and causality, a lower limit on the number of bits in the universe relative to its mass may be derived. Furthermore, these limits indicate particles that putatively travel at the speed of light -- the photon and/or graviton -- have a non-zero mass $m \geq 10^{-68}~$kg. This result is found to be in excellent agreement with current experimental mass bounds on the graviton and photon, suggesting that entropic gravity may be the result of a (recent) softly-broken local symmetry. Stronger bounds emerge from consideration of ultradense matter such as neutron stars, yielding limits of $m \geq 10^{-48}-10^{-50}~$kg, barely within the experimental photon range and outside that of the graviton. We find that for black holes these criteria cannot be satisfied, and suggest some possible implications of this result.