Loop quantum cosmology, non-Gaussianity, and CMB power asymmetry

Understand

We argue that the anomalous power asymmetry observed in the cosmic microwave background (CMB) may have originated in a cosmic bounce preceding inflation.

• In loop quantum cosmology (LQC) the big bang singularity is generically replaced by a bounce due to quantum gravitational effects.
• We compute the spectrum of inflationary non-Gaussianity and show that strong correlation between observable scales and modes with longer (super-horizon) wavelength arise as a consequence of the evolution of perturbations across the LQC bounce.
• These correlations are strongly scale dependent and induce a dipole-dominated modulation on large angular scales in the CMB, in agreement with observations.