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Schlagwörter:
General Relativity and Quantum Cosmology, gr-qc,Astrophysics, Cosmology and Extragalactic Astrophysics, astro-ph.CO,High Energy Physics - Theory, hep-th
Zusammenfassung:
We study in detail the power spectra of scalar and tensor perturbations
generated during inflation in loop quantum cosmology (LQC). After clarifying in
a novel quantitative way how inverse-volume corrections arise in inhomogeneous
settings, we show that they can generate large running spectral indices, which
generally lead to an enhancement of power at large scales. We provide explicit
formulas for the scalar/tensor power spectra under the slow-roll approximation,
by taking into account corrections of order higher than the runnings. We place
observational bounds on the inverse-volume quantum correction \delta ~ a^{-
\sigma} (\sigma >0, $a$ is the scale factor) and the slow-roll parameter
\epsilon_V for power-law potentials as well as exponential potentials by using
the data of WMAP 7yr combined with other observations. We derive the
constraints on \delta for two pivot wavenumbers k_0 for several values of
\delta. The quadratic potential can be compatible with the data even in the
presence of the LQC corrections, but the quartic potential is in tension with
observations. We also find that the upper bounds on \delta (k_0) for given
\sigma and k_0 are insensitive to the choice of the inflaton potentials.
