Ellipsoidal Universe Can Solve The CMB Quadrupole Problem
TLDR
In this paper, the large-scale spatial geometry of our universe was shown to be plane-symmetric with eccentricity at decoupling or order 10^{-2, and the quadrupole amplitude can be reduced without affecting higher multipoles of the angular power spectrum of the temperature anisotropy.Abstract:
The recent three-year WMAP data have confirmed the anomaly concerning the low quadrupole amplitude compared to the best-fit \Lambda CDM prediction. We show that, allowing the large-scale spatial geometry of our universe to be plane-symmetric with eccentricity at decoupling or order 10^{-2}, the quadrupole amplitude can be drastically reduced without affecting higher multipoles of the angular power spectrum of the temperature anisotropy.read more
Citations
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Imprints of a Primordial Preferred Direction on the Microwave Background
TL;DR: In this article, the authors examined the consequences of a small breaking of rotational invariance during the inflationary era when the primordial density fluctuations were generated, and provided explicit formulas for the expected amplitudes of the spherical-harmonic coefficients.
Journal ArticleDOI
Primordial magnetogenesis
TL;DR: In this paper, the authors review the question of primordial magnetism and consider the limits set on their strength by the current observational data and also discuss how future observations could be used to decide whether the large-scale magnetic fields we see in the universe today are truly primordial or not.
Journal ArticleDOI
Cosmological magnetic fields from inflation and backreaction
TL;DR: In this paper, the backreaction problem in a mechanism of magnetogenesis from inflation was studied and it was shown that the creation of primordial magnetic fields is significantly suppressed due to the back-reaction.
Journal ArticleDOI
Anisotropic Dark Energy: Dynamics of Background and Perturbations
Tomi S. Koivisto,David F. Mota +1 more
TL;DR: In this paper, the authors investigate cosmologies where the accelerated expansion of the Universe is driven by a field with an anisotropic equation of state, and they model such scenarios within the Bianchi I framework, introducing two skewness parameters to quantify the deviation of pressure from isotropy.
Journal ArticleDOI
CMB Anisotropies and Inflation from Non-Standard Spinors
TL;DR: In this paper, the authors explore the imprints that spinor driven inflation would leave on the cosmic microwave background anisotropies, and show that it is natural to expect an anisotropic inflationary expansion of the universe which has the effect of suppressing the low multipole amplitude of the primordial power spectrum, while at the same time to provide the usual inflationary features.
References
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First year Wilkinson Microwave Anisotropy Probe (WMAP) observations: Determination of cosmological parameters
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TL;DR: In this article, the authors find that the emerging standard model of cosmology, a flat -dominated universe seeded by a nearly scale-invariant adiabatic Gaussian fluctuations, fits the WMAP data.
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Empty space-times admitting a three parameter group of motions
TL;DR: In this paper, it is shown that if T, = 0 and there are no singularities anywhere in the g9, then equations (1.1) which take the form of second order partial differential equations for the g, and their solutions involve arbitrary functions which are to be determined from physical data expressed as initial values or boundary conditions.
Journal ArticleDOI
Extragalactic magnetic fields
TL;DR: In this paper, the observational methods for detecting and measuring extragalactic magnetic fields are discussed, along with some new indirect methods which could be used for inferring field strengths at large redshifts which are otherwise beyond the reach of direct measurement.
Journal ArticleDOI
Magnetic Fields in the Early Universe
Dario Grasso,H. Rubinstein +1 more
TL;DR: In this paper, the authors discuss magnetic fields in the early universe, their origin, their possible detection, and their limits and values today and at early times, and discuss the possible detection of magnetic fields.
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