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Related papers: Which FLRW comoving 3-manifold is preferred observ…

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We study dynamics of Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime based on the ghost-free bigravity theory. Assuming the coupling parameters guaranteeing the existence of de Sitter space as well as Minkowski spacetime, we find two…

General Relativity and Quantum Cosmology · Physics 2014-03-26 Katsuki Aoki , Kei-ichi Maeda

Several analyses of the microwave sky maps from the Wilkinson Microwave Anisotropy Probe (WMAP) have drawn attention to alignments amongst the low-order multipoles. Amongst the various possible explanations, an effect of cosmic topology has…

Astrophysics · Physics 2009-11-13 James G. Cresswell , Andrew R. Liddle , Pia Mukherjee , Alain Riazuelo

The Cosmic Microwave Background (CMB) provides a precious window on fundamental physics at very high energy scales, possibly including quantum gravity, GUTs and supersymmetry. The CMB has already enabled defect-based rivals to inflation to…

Astrophysics · Physics 2009-09-11 John Ellis

I use the most recent cosmic microwave background (CMB) anisotropy measurements to constrain the leading cold dark matter models in the Omega_m - Omega_lambda plane. A narrow triangular region is preferred. This triangle is elongated in…

Astrophysics · Physics 2009-10-30 Charles H. Lineweaver

The statistical expectation values of the temperature fluctuations of cosmic microwave background (CMB) are assumed to be preserved under rotations of the sky. We investigate the statistical isotropy of the CMB anisotropy maps recently…

Astrophysics · Physics 2007-05-23 Tarun Souradeep , Amir Hajian

Recent cosmic microwave background (CMB) observations put strong constraints on the spatial curvature via estimation of the parameter $\Omega_k$ assuming an almost scale invariant primordial power spectrum. We study the evolution of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-31 Béatrice Bonga , Brajesh Gupt , Nelson Yokomizo

Recent measurements of the cosmic microwave background radiation (CMB), particularly when combined with other datasets, have revolutionised our knowledge of the values of the basic cosmological parameters. Here we summarize the state of…

Astrophysics · Physics 2007-05-23 Ariel G. Sanchez , Carlton M. Baugh

We repeat and extend the analysis of Eriksen et al 2004 and Hansen et al 2004 testing the isotropy of the Cosmic Microwave Background (CMB) fluctuations. We find that the hemispherical power asymmetry previously reported for the largest…

Astrophysics · Physics 2014-11-18 F. K. Hansen , A. J. Banday , K. M. Gorski , H. K. Eriksen , P. B. Lilje

A class of exact, anisotropic cosmological solutions to the vacuum Brans-Dicke theory of gravity is considered within the context of the pre-big bang scenario. Included in this class are the Bianchi type III, V and VI_h models and the…

General Relativity and Quantum Cosmology · Physics 2016-08-31 D. Clancy , J. E. Lidsey , R. Tavakol

The bispectrum of the cosmic microwave background (CMB) generated by a correlation between a time-dependent gravitational potential and the weak gravitational lensing effect provides a direct measurement of the influence of dark energy on…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Veronika Junk , Eiichiro Komatsu

The assumption of a Friedmann-Lema\^itre-Roberton-Walker (FLRW) Universe is one of the fundamental pillars of modern Cosmology. It is crucial to confront it against cosmological observations in order to confirm (or rule out) the validity of…

General Relativity and Quantum Cosmology · Physics 2022-02-16 Carlos Bengaly

We study the loop quantum cosmology of a flat Friedmann-Lemaitre-Robertson-Walker space-time with a Maxwell field. We show that many of the qualitative properties derived for the case of a massless scalar field also hold for a Maxwell…

General Relativity and Quantum Cosmology · Physics 2015-01-07 Tomasz Pawlowski , Roberto Pierini , Edward Wilson-Ewing

We present a formalism for analyzing interferometric observations of Cosmic Microwave Background (CMB) anisotropy and polarization data. The formalism is based upon the ell-space expansion of the angular power spectrum favoured in recent…

Astrophysics · Physics 2009-08-18 Martin White , John E. Carlstrom , Mark Dragovan , William L. Holzapfel

We continue investigation of the hidden plane-mirror symmetry in the distribution of excursion sets in cosmic microwave background (CMB) temperature anisotropy maps, previously noticed in the three-year data of the Wilkinson microwave…

(Abridged) The WMAP 5-year data strongly limit deviations from the minimal LCDM model. We constrain the physics of inflation via Gaussianity, adiabaticity, the power spectrum shape, gravitational waves, and spatial curvature. We also…

In this study of the modified $f(Q)$ theory of gravity in the spatially flat Friedmann-Lema\^itre-Robertson-Walker (FLRW) spacetime, we explore all the affine connections compatible with the symmetric teleparallel structure; three classes…

General Relativity and Quantum Cosmology · Physics 2024-10-25 Ganesh Subramaniam , Avik De , Tee-How Loo , Yong Kheng Goh

Using an approximate likelihood method adapted to band--power estimates, we analyze the ensemble of first generation cosmic microwave background anisotropy experiments to deduce constraints over a six--dimensional parameter space describing…

Astrophysics · Physics 2011-05-23 M. Le Dour , M. Douspis , J. G. Bartlett , A. Blanchard

The amplitudes of the quadrupole and octopole measured from the Wilkinson Microwave Anisotropy Probe (WMAP) appear to be lower than expected according to the concordance Lambda CDM cosmology. However, the pseudo-Cl estimator used by the…

Astrophysics · Physics 2009-07-09 G. Efstathiou

Spatially flat loitering universe models have recently been shown to arise in the context of brane world scenarios. Such models allow more time for structure formation to take place at high redshifts, easing, e.g., the tension between the…

Astrophysics · Physics 2009-11-10 O. Elgaroy , D. F. Mota , T. Multamaki

A conventional explanation of the dipole anisotropy of the cosmic microwave background (CMB) radiation is in terms of the Doppler effect: our galaxy is moving with respect to CMB frame with $ \sim 600 ~ km ~ s^{-1} $. However, as the deep…

Astrophysics · Physics 2007-05-23 M. Jaroszynski , B. Paczynski