CMB spectral μ-distortion of multiple inflation scenario

In multiple inflation scenario having two inflations with an intermediate matter-dominated phase, the power spectrum is estimated to be enhanced on scales smaller than the horizon size at the beginning of the second inflation, k>kb. We require kb>10Mpc−1 to make sure that the enhanced power spectrum is consistent with large scale observation of cosmic microwave background (CMB). We consider the CMB spectral distortions generated by the dissipation of acoustic waves to constrain the power spectrum. The μ-distortion value can be 102 times larger than the expectation of the standard ΛCDM model (μΛCDM≃2×10−8) for kb≲103Mpc−1, while the y-distortion is hardly affected by the enhancement of the power spectrum.