Regular Article - Theoretical Physics
k-Inflation in noncommutative space–time
Shanghai United Center for Astrophysics (SUCA), Shanghai Normal University, 100 Guilin Road, Shanghai, 200234, People’s Republic of China
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Accepted: 21 January 2015
Published online: 3 February 2015
The power spectra of the scalar and tensor perturbations in the noncommutative k-inflation model are calculated in this paper. In this model, all the modes created when the stringy space–time uncertainty relation is satisfied, and they are generated inside the sound/Hubble horizon during inflation for the scalar/tensor perturbations. It turns out that a linear term describing the noncommutative space–time effect contributes to the power spectra of the scalar and tensor perturbations. Confronting the general noncommutative k-inflation model with latest results from Planck and BICEP2, and taking and as free parameters, we find that it is well consistent with observations. However, for the two specific models, i.e. the tachyon and DBI inflation models, it is found that the DBI model is not favored, while the tachyon model lies inside the contour, when the e-folding number is assumed to be around .
© SIF and Springer-Verlag Berlin Heidelberg, 2015