Explaining low-l Anomalies in the CMB Power Spectrum with Resonant Superstring Excitations during Inflation.

We explore the possibility that both the suppression of the $\ell = 2$ multipole moment of the power spectrum of the cosmic microwave background temperature fluctuations and the possible dip in the power spectrum for $\ell = 10-30$ can be explained as well as a possible new dip at $\ell \approx 60$ as the result of the resonant creation of sequential excitations of a fermionic (or bosonic) closed superstring that couples to the inflaton field. We utilize the simple example of a D=26 closed bosonic string with one toroidal compact dimension as an illustration of how string excitations might imprint themselves on the power spectrum of the CMB. We consider the possibilities of successive momentum states, winding states, or oscillations on the string as the source of the three possible dips in the power spectrum.Although the evidence of the dips at $\ell \approx 20 $ and $\ell \approx 60$ are of marginal statistical significance, and there are other possible interpretations of these features, this might constitute the first observational evidence of the existence of successive superstring excitations in Nature.