  We interpret the lack of large-angle temperature correlations and the
apparent even-odd parity imbalance, observed in the cosmic microwave background
by COBE, WMAP and Planck satellite missions, as a possible stringy signal
ultimately stemming from a composite inflaton field (e.g. a fermionic
condensate). Based on causality arguments and a Fourier analysis of the angular
two-point correlation function, two infrared cutoffs $k_{\rm min}^{\rm
even,odd}$ are introduced in the CMB power spectrum associated, respectively,
with periodic and antiperiodic boundary conditions of the fermionic
constituents (echoing the Neveu-Schwarz-Ramond model in superstring theory),
without resorting to any particular model.
