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The quantization of the massless minimally coupled (mmc) scalar field in deSitter spacetime is known to be a non-trivial problem due to the appearance ofstrong infrared (IR) effects. In particular, the scale-invariance of the CMBpower-spectrum - certainly one of the most successful predictions of moderncosmology - is widely believed to be inconsistent with a de Sitter invariantmmc two-point function.  Using a Cesaro-summability technique to properly define an otherwisedivergent Fourier transform, we show in this Letter that de Sitter symmetrybreaking is \emph{not} a necessary consequence of the scale-invariantfluctuation spectrum. We also generalize our result to the tachyonic scalarfields, i.e the discrete series of representations of the de Sitter group, thatsuffer from similar strong IR effects.

Do scale-invariant fluctuations imply the breaking of de Sitter invariance?