Alleviating the Tension in the Cosmic Microwave Background using Planck-Scale Physics

Understand

Certain anomalies in the CMB bring out a tension between the six-parameter flat $\Lambda$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.