Cosmic microwave background anomalies viewed via Gumbel Statistics
نویسندگان
چکیده
We describe and discuss the application of Gumbel statistics, which model extreme events, to WMAP 5-year measurements of the cosmic microwave background. We find that temperature extrema of the CMB are well modelled by the Gumbel formalism and describe tests for Gaussianity that the approach can provide. Comparison to simulations reveals Gumbel statistics to have only weak discriminatory power for the conventional statistic: f NL < 1000, though it may probe other regimes of non-Gaussianity. Tests based on hemispheric cuts reveal interesting alignment with other reported CMB anomalies. The approach has the advantage of model independence and may find further utility with smaller scale data.
منابع مشابه
Probing the Origin of the Large-angle CMB Anomalies
It has been argued that the large-angle cosmic microwave background anisotropy has anomalies at ∼ 3σ level. We review various proposed ideas to explain the origin of the anomalies and discuss how we can constrain the proposed models using future observational data.
متن کاملCosmic microwave background anomalies in an open universe.
We argue that the observed large-scale cosmic microwave anomalies, discovered by WMAP and confirmed by the Planck satellite, are most naturally explained in the context of a marginally open universe. Particular focus is placed on the dipole power asymmetry, via an open universe implementation of the large-scale gradient mechanism of Erickcek et al. Open inflation models, which are motivated by ...
متن کاملLocal Voids as the Origin of Large-angle Cosmic Microwave Background Anomalies I
We explore the large angular scale temperature anisotropies in the cosmic microwave background due to expanding homogeneous local voids at redshift z . 1. A compensated spherically symmetric homogeneous dust-filled void with radius ∼ 3× 102h−1Mpc, and density contrast δ ∼ −0.3 can be observed as a cold spot with a temperature anisotropy ∆T/T ∼ −1× 10−5 surrounded by a slightly hotter ring. We f...
متن کاملLocal Voids as the Origin of Large-angle Cosmic Microwave Background Anomalies
We explore the large angular scale temperature anisotropies in the cosmic microwave background due to expanding homogeneous local voids at redshift z . 1. A compensated spherically symmetric homogeneous dust-filled void with radius ∼ 3× 102h−1Mpc, and density contrast δ ∼ −0.3 can be observed as a cold spot with a temperature anisotropy ∆T/T ∼ −1× 10−5 surrounded by a slightly hotter ring. We f...
متن کاملLarge-Angle Anomalies in the CMB
We review the recently found large-scale anomalies in the maps of temperature anisotropies in the cosmic microwave background. These include alignments of the largest modes of CMB anisotropy with each other and with geometry and direction of motion of the solar ssystem, and the unusually low power at these largest scales. We discuss these findings in relation to expectation from standard inflat...
متن کامل