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A phenomenological model is described for Cosmic Microwave Background Radiation (CMBR) evolution with dark energy an essential ingredient in the form of a $k-$essence scalar field. The following features of this evolution can be…

General Relativity and Quantum Cosmology · Physics 2014-06-11 Abhijit Bandyopadhyay , Debashis Gangopadhyay , Arka Moulik

Quasi-single field inflation predicts a peculiar momentum dependence in the squeezed limit of the primordial bispectrum which smoothly interpolates between the local and equilateral models. This dependence is directly related to the mass of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Emiliano Sefusatti , James R. Fergusson , Xingang Chen , E. P. S. Shellard

Cosmological measurements over the next decade will enable us to shed light on the content and evolution of the Universe. Complementary measurements of the Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations are expected to…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-10 Siddharth Mishra-Sharma , David Alonso , Joanna Dunkley

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 fluctuations of the cosmic microwave background (CMB) are investigated for a hyperbolic universe with finite volume. Four-component models with radiation, matter, vacuum energy, and an extra spatially constant dark energy X-component…

Astrophysics · Physics 2015-06-24 R. Aurich , F. Steiner

In the near future, observations of the cosmic microwave background (CMB) anisotropies will provide accurate determinations of many fundamental cosmological parameters. In this paper, we analyse degeneracies among cosmological parameters to…

Astrophysics · Physics 2009-10-30 G. Efstathiou , J. R. Bond

The Planck experiment will soon provide a very accurate measurement of Cosmic Microwave Background anisotropies. This will let cosmologists determine most of the cosmological parameters with unprecedented accuracy. Future experiments will…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-24 Silvia Galli , Matteo Martinelli , Alessandro Melchiorri , Luca Pagano , Blake D. Sherwin , David N. Spergel

Astrophysical tests of the stability of dimensionless fundamental couplings, such as the fine-structure constant $\alpha$ and the proton-to-electron mass ratio $\mu$, are an optimal probe of new physics. There is a growing interest in these…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-07 A. C. O. Leite , C. J. A. P. Martins

Using a gauge-invariant formalism we derive and solve the perturbed cosmological equations for the BSBM theory of varying fine structure 'constant'. We calculate the time evolution of inhomogeneous perturbations of the fine structure…

General Relativity and Quantum Cosmology · Physics 2009-11-07 John D. Barrow , D. F. Mota

Observations of the Cosmic Microwave Background (CMB) are discussed, with particular emphasis on current ground-based experiments and on future satellite, balloon and interferometer experiments. Observational techniques and the effects of…

Astrophysics · Physics 2009-10-31 A. N. Lasenby , A. W. Jones , Y. Dabrowski

A new component of the cosmic medium, a light scalar field or ''quintessence '', has been proposed recently to explain cosmic acceleration with a dynamical cosmological constant. Such a field is expected to be coupled explicitely to…

Astrophysics · Physics 2010-02-18 Luca Amendola

Fundamental physical constants need not be constant, neither spatially nor temporally. -- This seeming simple statement has profound implications for a wide range of physical processes and interactions, and can be probed through a number of…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-22 Jens Chluba , Luke Hart

We perform a likelihood analysis of the recently released BOOMERanG and MAXIMA data, allowing for the possibility of a time-varying fine-structure constant. We find that in general this data prefers a value of $\alpha$ that was smaller in…

Astrophysics · Physics 2008-11-26 P. P. Avelino , C. J. A. P. Martins , G. Rocha , P. Viana

The next generation of Cosmic Microwave Background experiments will produce cosmic variance limited observations over a large fraction of sky and for a large range of multipoles. In this work we discuss different consistency tests that can…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-22 Thibaut Louis , Xavier Garrido , Adam Soussana , Matthieu Tristram , Sophie Henrot-Versillé , Sylvain Vanneste

It is well known that estimating cosmological parameters from cosmic microwave background (CMB) data alone results in a significant degeneracy between the total neutrino mass and several other cosmological parameters, especially the Hubble…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-28 Will Sutherland

In this work we investigate the effects of the primordial magnetic fields on cosmic microwave background anisotropies (CMB). Based on cosmological magnetohydrodynamic (MHD) simulations we calculate the CMB anisotropy spectra and…

Astrophysics · Physics 2009-11-13 Hiroyuki Tashiro , Naoshi Sugiyama , Robi Banerjee

In this note we observe that Webb and co-workers' observation of an evolving fine structure constant has since been reconfirmed. We also confirm Kuhne's contention that this implies a cosmological constant and exhibit a cosmological…

General Physics · Physics 2007-05-23 B. G. Sidharth

We investigate the cosmological observational test of the extended quintessence model, i.e. a scalar-tensor gravity model with a scalar field potential serving as dark energy, by using the Planck 2018 cosmic microwave background (CMB) data,…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 Gong Cheng , Fengquan Wu , Xuelei Chen

We consider the distribution of the non-Gaussian signal induced by weak lensing on the primary total intensity cosmic microwave background (CMB) anisotropies. Our study focuses on the three point statistics exploiting an harmonic analysis…

Astrophysics · Physics 2009-11-10 Fabio Giovi , Carlo Baccigalupi , Francesca Perrotta

We discuss present and future cosmological constraints on variations of the fine structure constant $\alpha$ induced by an early dark energy component having the simplest allowed (linear) coupling to electromagnetism. We find that current…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-08 Erminia Calabrese , Eloisa Menegoni , C. J. A. P. Martins , Alessandro Melchiorri , Graca Rocha
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