Alignments of parity even/odd-only multipoles in CMB
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Issue Date
2017-08-17Author
Aluri, Pavan K.
Ralston, John P.
Weltman, Amanda
Publisher
SpringerOpen
Type
Article
Article Version
Scholarly/refereed, publisher version
Rights
© 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.
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Show full item recordAbstract
We compare the statistics of parity even and odd multipoles of the cosmic microwave background (CMB) sky from Planck full mission temperature measurements. An excess power in odd multipoles compared to even multipoles has previously been found on large angular scales. Motivated by this apparent parity asymmetry, we evaluate directional statistics associated with even compared to odd multipoles, along with their significances. Primary tools are the Power tensor and Alignment tensor statistics. We limit our analysis to the first 60 multipoles i.e. l = [2, 61]. We find no evidence for statistically unusual alignments of even parity multipoles. More than one independent statistic finds evidence for alignments of anisotropy axes of odd multipoles, with a significance equivalent to ∼2σ or more. The robustness of alignment axes is tested by making Galactic cuts and varying the multipole range. Very interestingly, the region spanned by the (a)symmetry axes is found to broadly contain other parity (a)symmetry axes previously observed in the literature.
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Citation
Pavan K. Aluri, John P. Ralston, Amanda Weltman; Alignments of parity even/odd-only multipoles in CMB, Monthly Notices of the Royal Astronomical Society, Volume 472, Issue 2, 1 December 2017, Pages 2410–2421, https://doi.org/10.1093/mnras/stx2112
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