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

TL;DR

This paper explores how noncommutative modifications to the inflaton action induce oscillations in the initial power spectrum, improving fit to CMB data and constraining noncommutative parameters.

Contribution

It introduces a noncommutative inflation model with oscillatory initial power spectrum, providing better data fit and precise bounds on noncommutative parameters.

Findings

Oscillations in the power spectrum improve WMAP fit by Δχ² ~ 8.5.

Noncommutative parameters constrained to 10^{16} GeV or 10^{4} GeV.

Model predicts specific initial state effects on CMB spectrum.

Abstract

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 $\chi^{2}$ about $\Delta\chi^{2}\sim 8.5$. As a bonus, from the parameter estimation done in this work, we show that the noncommutative parameters can be precisely bound to $10^{16}$ GeV or $10^{4}$ GeV depending on the inflation scale.