The Atacama Cosmology Telescope: Delensed Power Spectra and Parameters

Understand

We present LCDM cosmological parameter constraints obtained from delensed microwave background power spectra.

• Lensing maps from a subset of DR4 data from the Atacama Cosmology Telescope (ACT) are used to undo the lensing effect in ACT spectra observed at 150 and 98 GHz.
• At 150 GHz, we remove the lensing distortion with an effective efficiency of 30% (TT), 30% (EE), 26% (TE) and 20% (BB); this results in detections of the delensing effect at 8.7 sigma (TT), 5.1 sigma (EE), 2.6 sigma (TE), and 2.4 sigma (BB) significance.
• The combination of 150 and 98 GHz TT, EE, and TE delensed spectra is well fit by a standard LCDM model.