Short Distance Physics and Initial State Effects on the CMB Power Spectrum and Cosmological Constant

We investigate a modification in the action of inflaton due to noncommutativity leads to a nonstandard initial vacuum and oscillatory corrections in the initial power spectrum. We show that the presence of these oscillations causes a drop in the WMAP χ2 about ∆χ2 ∼ 8.5. We also show that this nonstandard initial vacuum state can provide a rolling in cosmological constant. As a bonus, from the parameter estimation done in this work, we show that the noncommutative parameters can be precisely bound to 1016 GeV or 104 GeV depending on the inflation scale. e-mail: [email protected] 1