Certain anomalies in the CMB bring out a tension between the six-parameter flat $\mathrm{\Lambda }\mathrm{CDM}$ model and the CMB data. We revisit the PLANCK analysis with loop quantum cosmology (LQC) predictions and show that LQC alleviates both the large-scale power anomaly and the tension in the lensing amplitude. These differences arise because, in LQC, the primordial power spectrum is scale dependent for small $k$, with a specific power suppression. We conclude with a prediction of larger optical depth and power suppression in the $B$-mode polarization power spectrum on large scales.

• Received 2 February 2020
• Revised 19 May 2020
• Accepted 9 July 2020

DOI:https://doi.org/10.1103/PhysRevLett.125.051302