A note on trans-Planckian tail effects

Graef, L.L. (Department of Physics, McGill University, 3600 University Street, Montréal, QC, H3A 2T8 Canada) (Instituto de Física, Universidade de São Paulo, Rua do Matão travessa R, São Paulo, SP, 05508-090 Brazil) ; Brandenberger, R. (Department of Physics, McGill University, 3600 University Street, Montréal, QC, H3A 2T8 Canada)

30 January 2017

Abstract: We study the proposal by Mersini et al. [1] that the observed dark energy might be explained by the back-reaction of the set of tail modes in a theory with a dispersion relation in which the mode frequency decays exponentially in the trans-Planckian regime. The matter tail modes are frozen out, however they induce metric fluctuations. The energy-momentum tensor with which the tail modes effect the background geometry obtains contributions from both metric and matter fluctuations. We calculate the equation of state induced by the tail modes taking into account the gravitational contribution. We find that, in contrast to the case of frozen super-Hubble cosmological fluctuations, in this case the matter perturbations dominate, and they yield an equation of state which to leading order takes the form of a positive cosmological constant.


Published in: JCAP 1509 (2015) 032
Published by: Institute of Physics Publishing/SISSA
DOI: 10.1088/1475-7516/2015/09/032
arXiv: 1505.02374
License: CC-BY-3.0



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