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Negative running of the spectral index, hemispherical asymmetry and the consistency of Planck with large r

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Negative running of the spectral index, hemispherical asymmetry and the consistency of Planck with large r. / McDonald, John.

In: Journal of Cosmology and Astroparticle Physics, Vol. 2014, No. 11, 012, 11.2014.

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McDonald, John. / Negative running of the spectral index, hemispherical asymmetry and the consistency of Planck with large r. In: Journal of Cosmology and Astroparticle Physics. 2014 ; Vol. 2014, No. 11.

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@article{6e7c3100987f467daf0ebdf802120196,
title = "Negative running of the spectral index, hemispherical asymmetry and the consistency of Planck with large r",
abstract = "Planck favours a negative running of the spectral index, with the likelihood being dominated by low multipoles l less than or similar to 50 and no preference for running at higher /. A negative spectral index is also necessary for the 2-sigma Planck upper bound on the tensor-to-scalar ratio r to be consistent with values significantly larger than 0.1. Planck has also observed a hemispherical asymmetry of the CMB power spectrum, again mostly at low multipoles. Here we consider whether the physics responsible for the hemispherical asymmetry could also account for the negative running of the spectral index and the consistency of Planck with a large value of r. A negative running of the spectral index can be generated if the hemispherical asymmetry is due to a scale- and space-dependent modulation which suppresses the CMB power spectrum at low multipoles. We show that the observed hemispherical asymmetry at low l can be generated while satisfying constraints on the asymmetry at higher l and generating a negative spectral index of the right magnitude to account for the Planck observation and to allow Planck to be consistent with a large value of r.",
keywords = "cosmological parameters from CMBR, cosmological perturbation theory, CMBR theory, POWER ASYMMETRY, WMAP DATA, SKY",
author = "John McDonald",
year = "2014",
month = nov
doi = "10.1088/1475-7516/2014/11/012",
language = "English",
volume = "2014",
journal = "Journal of Cosmology and Astroparticle Physics",
issn = "1475-7516",
publisher = "IOP Publishing",
number = "11",

}

RIS

TY - JOUR

T1 - Negative running of the spectral index, hemispherical asymmetry and the consistency of Planck with large r

AU - McDonald, John

PY - 2014/11

Y1 - 2014/11

N2 - Planck favours a negative running of the spectral index, with the likelihood being dominated by low multipoles l less than or similar to 50 and no preference for running at higher /. A negative spectral index is also necessary for the 2-sigma Planck upper bound on the tensor-to-scalar ratio r to be consistent with values significantly larger than 0.1. Planck has also observed a hemispherical asymmetry of the CMB power spectrum, again mostly at low multipoles. Here we consider whether the physics responsible for the hemispherical asymmetry could also account for the negative running of the spectral index and the consistency of Planck with a large value of r. A negative running of the spectral index can be generated if the hemispherical asymmetry is due to a scale- and space-dependent modulation which suppresses the CMB power spectrum at low multipoles. We show that the observed hemispherical asymmetry at low l can be generated while satisfying constraints on the asymmetry at higher l and generating a negative spectral index of the right magnitude to account for the Planck observation and to allow Planck to be consistent with a large value of r.

AB - Planck favours a negative running of the spectral index, with the likelihood being dominated by low multipoles l less than or similar to 50 and no preference for running at higher /. A negative spectral index is also necessary for the 2-sigma Planck upper bound on the tensor-to-scalar ratio r to be consistent with values significantly larger than 0.1. Planck has also observed a hemispherical asymmetry of the CMB power spectrum, again mostly at low multipoles. Here we consider whether the physics responsible for the hemispherical asymmetry could also account for the negative running of the spectral index and the consistency of Planck with a large value of r. A negative running of the spectral index can be generated if the hemispherical asymmetry is due to a scale- and space-dependent modulation which suppresses the CMB power spectrum at low multipoles. We show that the observed hemispherical asymmetry at low l can be generated while satisfying constraints on the asymmetry at higher l and generating a negative spectral index of the right magnitude to account for the Planck observation and to allow Planck to be consistent with a large value of r.

KW - cosmological parameters from CMBR

KW - cosmological perturbation theory

KW - CMBR theory

KW - POWER ASYMMETRY

KW - WMAP DATA

KW - SKY

U2 - 10.1088/1475-7516/2014/11/012

DO - 10.1088/1475-7516/2014/11/012

M3 - Journal article

VL - 2014

JO - Journal of Cosmology and Astroparticle Physics

JF - Journal of Cosmology and Astroparticle Physics

SN - 1475-7516

IS - 11

M1 - 012

ER -