TY - JOUR
T1 - Probing primordial magnetism with off-diagonal correlators of CMB polarization
AU - Yadav, Amit
AU - Pogosian, Levon
AU - Vachaspati, Tanmay
PY - 2012/12/12
Y1 - 2012/12/12
N2 - Primordial magnetic fields (PMF) can create polarization B-modes in the cosmic microwave background (CMB) through Faraday rotation (FR), leading to nontrivial two-point and four-point correlators of the CMB temperature and polarization. We discuss the detectability of primordial magnetic fields using different correlators and evaluate their relative merits. We have fully accounted for the contamination by weak lensing, which contributes to the variance, but whose contribution to the four-point correlations is orthogonal to that of FR. We show that a Planck-like experiment can detect scale-invariant PMF of nG strength using the FR diagnostic at 90GHz, while realistic future experiments at the same frequency can detect 10-10G. Utilizing multiple frequencies will improve on these prospects, making FR of CMB a powerful probe of scale-invariant PMF.
AB - Primordial magnetic fields (PMF) can create polarization B-modes in the cosmic microwave background (CMB) through Faraday rotation (FR), leading to nontrivial two-point and four-point correlators of the CMB temperature and polarization. We discuss the detectability of primordial magnetic fields using different correlators and evaluate their relative merits. We have fully accounted for the contamination by weak lensing, which contributes to the variance, but whose contribution to the four-point correlations is orthogonal to that of FR. We show that a Planck-like experiment can detect scale-invariant PMF of nG strength using the FR diagnostic at 90GHz, while realistic future experiments at the same frequency can detect 10-10G. Utilizing multiple frequencies will improve on these prospects, making FR of CMB a powerful probe of scale-invariant PMF.
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U2 - 10.1103/PhysRevD.86.123009
DO - 10.1103/PhysRevD.86.123009
M3 - Article
AN - SCOPUS:84871053382
SN - 1550-7998
VL - 86
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
IS - 12
M1 - 123009
ER -