Quantum state correction of relic gravitons from quantum gravity

Abstract

The semiclassical approach to quantum gravity would yield the Schrödinger formalism for the wave function of metric perturbations or gravitons plus quantum gravity correcting terms in pure gravity; thus, in the inflationary scenario, we should expect correcting effects to the relic graviton (Zel'dovich) spectrum of the order of (λ/m 2 P l ). These, on the other hand, could possibly be measured in a future experiment.

Emergence of classicality for primordial fluctuations: Concepts and analogies

“…The relations (6) and (7) define, of course, a Bogolubov transformation. It should be stressed that all the equations (6,7,8) are valid for the corresponding classical system, too, with the obvious difference that the quantities y k , p k , a k are no longer operators. Special interest will be attached to the quantity B(k) ≡ f * k g k , whose real and imaginary parts read…”

Wheeler-DeWitt equation and Feynman diagrams

“…(3.21). In contrast with S ab , this operator is nondegenerate because now 14) and the right-hand side represents here in view of (5.10) a functional matrix with the rank coinciding with the dimensionality of the gauge group. Now we have to consider briefly the properties of the obtained operator F ab .…”

“…In particular cases it was possible to evaluate these correction terms to find quantum gravitationally induced energy shifts [9,13]. It was also shown that these correction terms can in principle lead to observable effects in the spectrum of the cosmological background radiation [14].…”

Quantum Gravitational Contributions to the Cosmic Microwave Background Anisotropy Spectrum

“…We now want to calculate the quantum gravitational correction terms following from (5). (A possible effect on the relic graviton density is discussed along these lines in [15].) As mentioned above, we shall neglect the unitarity violating term in (5).…”