Cosmic discordance: Detection of a modulation in the primordial fluctuation spectrum

Journal Article · Thu Apr 15 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.083010· OSTI ID:21409557

Ichiki, Kiyotomo ^[1]; Nagata, Ryo ^[1]; Yokoyama, Jun'ichi ^[1]

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1. Research Center for the Early Universe, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

As a test of the standard inflationary cosmology, which generically predicts a nearly scale-invariant spectrum of primordial curvature fluctuations, we perform a Markov-Chain Monte-Carlo analysis to search for possible modulations in the power spectrum and determine its shape together with the cosmological parameters using cosmic microwave background radiation data. By incorporating various three-parameter features on the simple power-law spectrum, we find an oscillatory modulation localized around the comoving wave number k{approx_equal}0.009 Mpc{sup -1} at 99.995% confidence level which improves the log-likelihood as much as -{Delta}2lnL{identical_to}{Delta}{chi}{sub eff}{sup 2}=-22. This feature can be detected even if we use only the cross correlation between the temperature and the E-mode polarization anisotropies.

• OSTI ID: 21409557
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 8; Other Information: DOI: 10.1103/PhysRevD.81.083010; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANISOTROPY
CORRELATIONS
COSMOLOGY
FLUCTUATIONS
INFLATIONARY UNIVERSE
MARKOV PROCESS
MODULATION
MONTE CARLO METHOD
POLARIZATION
RELICT RADIATION
SIMULATION
SPECTRA
CALCULATION METHODS
COSMOLOGICAL MODELS
ELECTROMAGNETIC RADIATION
MATHEMATICAL MODELS
MICROWAVE RADIATION
RADIATIONS
STOCHASTIC PROCESSES
VARIATIONS