5 papers
BICEP/Keck XXI: Constraints on Early-Universe Parity Violation from Multipole-Dependent Birefringence
Keck Collaboration, P. A. R. Ade, Zeeshan Ahmed +94
We present the first constraints on multipole-dependent cosmic birefringence using CMB polarization data from the BK18 dataset, which combines observations from BICEP2, Keck Array,…
BICEP/Keck XIX: Extremely Thin Composite Polymer Vacuum Windows for BICEP and Other High Throughput Millimeter Wave Telescopes
Keck Collaboration, P. A. R. Ade, Z. Ahmed +90
Millimeter-wave refracting telescopes targeting the degree-scale structure of the cosmic microwave background (CMB) have recently grown to diffraction-limited apertures of over 0.5…
BICEP/Keck XX: Component-separated maps of polarized CMB and thermal dust emission using Planck and BICEP/Keck Observations through the 2018 Observing Season
Keck Collaboration, P. A. R. Ade, Z. Ahmed +94
We present component-separated polarization maps of the cosmic microwave background (CMB) and Galactic thermal dust emission, derived using data from the BICEP/Keck experiments thr…
Improved Absolute Polarization Calibrator for BICEP CMB Polarimeters
A. R. Polish, P. A. R. Ade, Z. Ahmed +89
Cosmic birefringence is a hypothesized parity violation in electromagnetism that predicts a frequency-independent polarization rotation as light propagates. This would rotate the l…
BICEP/Keck XVIII: Measurement of BICEP3 polarization angles and consequences for constraining cosmic birefringence and inflation
Keck Collaboration, P. A. R. Ade, Z. Ahmed +83
We use a custom-made calibrator to measure individual detectors' polarization angles of BICEP3, a small aperture telescope observing the cosmic microwave background (CMB) at 95GHz…