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The Axis of Evil: revisited. Kate Land. astro-ph/0611518, 0502237, 0507289. THE ISSUES. AXIS OF EVIL Planarity Alignments Low-power Ecliptic issues. OTHER Asymmetries Cold spot. PLANARITY & AOE.
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The Axis of Evil: revisited Kate Land astro-ph/0611518, 0502237, 0507289
THE ISSUES • AXIS OF EVIL • Planarity • Alignments • Low-power • Ecliptic issues • OTHER • Asymmetries • Cold spot The Axis of Evil Revisited. Kate Land
PLANARITY & AOE “Intriguingly, both the quadrupole and the octopole are seen to have power suppressed along a particular spatial axis, which lines up between the two, roughly towards (l, b) ~ (-110, 60) in Virgo.” Tegmark & al.PRD(68)123523 The Axis of Evil Revisited. Kate Land
m = 2 m = 0 A posteriori planarity Quadrupole l = 2 The Axis of Evil Revisited. Kate Land
m = 3 m = 1 A posteriori planarity Octopole l = 3 The Axis of Evil Revisited. Kate Land
‘Planarity’ is quite normal - BUT THE AXIS IS NOT! The Axis of Evil Revisited. Kate Land
Axis of Evil Independent of Gaussianity Hard to test The Axis of Evil Revisited. Kate Land
Multipoles share axis, and ratio Maximum Likelihood • Avoid instabilities • Allow model comparison (Bayesian V Freq) The Axis of Evil Revisited. Kate Land
‘Planarity’ l = 2, 3 m = l Parameters: ‘m-preference’ l = 2 - 5 m free Parameters: Models Null The Axis of Evil Revisited. Kate Land
Maximum Likelihood The Axis of Evil Revisited. Kate Land
Significance Compare to simulations Information criteria ‘planarity’ AIC ~ 2, BIC ~ 2.8 ‘m-pref’ AIC ~ 2.8, BIC ~ 0 Jeffreys’ scale > 2.5 ‘strong’ The Axis of Evil Revisited. Kate Land
Bayesian evidence The Axis of Evil Revisited. Kate Land
What can we conclude? • Evidence for AOE depends on model and method! • Similarly for ns<1 (Liddle astro-ph/0701113) • Important consequences • Combined with other anomalies • SYSTEMATICS Satellite, data pipeline, … • ASTROPHYSICAL EFFECT Foregrounds, local lensing, … • COSMOLOGICAL FEATURE Non-FLRW models, non-trivial topology, … The Axis of Evil Revisited. Kate Land
The Axis of Evil II - Summary Correlations seen for l = 2,3,4,5 But how do we test the significance? Propose a model Frequentist Bayesian Planarity m-preference The Axis of Evil Revisited. Kate Land
Priors The Axis of Evil Revisited. Kate Land
Cold spot (209,-57) Axis of Evil ~(260,60) Dipole (264,48) Virgo ~(260,70) Max asym axis (57,10) Ecliptic pole (96,30) SG pole (47,6) The Axis of Evil Revisited. Kate Land
Information criteria The Axis of Evil Revisited. Kate Land
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