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We test anisotropic dark energy models with the 7-year WMAP temperature observations data. In the presence of imperfect sources, due to large-scale gradients or anisotropies in the dark energy field, the CMB sky will be distorted…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-08 Magnus J. Axelsson , Frode K. Hansen , Tomi Koivisto , David F. Mota

We perform a comparison of the WMAP measurements with the predictions of quintessence cosmological models of dark energy. We consider a wide range of quintessence models, including: a constant equation-of-state; a simply-parametrized,…

Astrophysics · Physics 2007-05-23 Michael Doran

Temperature maps of the Cosmic Microwave Background (CMB) radiation, as those obtained by the Wilkinson Microwave Anisotropy Probe (WMAP), provide one of the most precise data sets to test fundamental hypotheses of modern cosmology. One of…

Astrophysics · Physics 2009-11-13 Armando Bernui , Constantino Tsallis , Thyrso Villela

We examine cosmic microwave background constraints on variations in the recombination history of the universe. We use a very general extension to the standard model of recombination characterized by two parameters, a and b, which multiply…

Astrophysics · Physics 2007-05-23 Angela M. Linn , Robert J. Scherrer

We present new measurements of the cosmic microwave background (CMB) polarization from the final season of the Cosmic Anisotropy Polarization MAPper (CAPMAP). The data set was obtained in winter 2004-2005 with the 7 m antenna in Crawford…

The Cosmic Microwave Background (CMB) power spectrum derived from the first year WMAP data demonstrates an intriguing lack of power at large scales that cannot be accounted for within the framework of the standard cosmological model. We…

Astrophysics · Physics 2009-11-11 Anastasia Niarchou , Andrew H. Jaffe

We present observational constraints on a scalar-tensor gravity theory by $\chi^2$ test for CMB anisotropy spectrum. We compare the WMAP temperature power spectrum with the harmonic attractor model, in which the scalar field has its…

Astrophysics · Physics 2009-11-10 Ryo Nagata , Takeshi Chiba , Naoshi Sugiyama

We have estimated the CMB variance from the three-year WMAP data, finding a value which is significantly lower than the one expected from Gaussian simulations using the WMAP best-fit cosmological model, at a significance level of 98.7 per…

Noncommutative inflation is based upon the consideration of some effects of the space-time uncertainty principle motivated by ideas from string/M theory. The CMB anisotropies may carry a signature of this very early Universe correction from…

Astrophysics · Physics 2009-11-11 Xin Zhang , Feng-Quan Wu

We forecast the ability of cosmic microwave background (CMB) temperature and polarization datasets to constrain theories of eternal inflation using cosmic bubble collisions. Using the Fisher matrix formalism, we determine both the overall…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-21 Stephen M. Feeney , Franz Elsner , Matthew C. Johnson , Hiranya V. Peiris

One of the characteristics of the "Matter Bounce" scenario, an alternative to cosmological inflation for producing a scale-invariant spectrum of primordial adiabatic fluctuations on large scales, is a break in the power spectrum at a…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Hong Li , Jun-Qing Xia , Robert Brandenberger , Xinmin Zhang

There are several studies proposing phenomenological consequences of a deformation of special and general relativity. Here, we cast novel constraints on the deformation parameter of a metric in the cotangent bundle accounting for a curved…

General Relativity and Quantum Cosmology · Physics 2020-11-18 J. J. Relancio , S. Liberati

We consider the hypothesis that nonlocal, omnidirectional, causally-coherent quantum entanglement of inflationary horizons may account for some well-known measured anomalies of Cosmic Microwave Background (CMB) anisotropy on large angular…

General Relativity and Quantum Cosmology · Physics 2022-02-16 Craig Hogan , Stephan S. Meyer

If the hemispherical power asymmetry observed in the cosmic microwave background (CMB) on large angular scales is attributable to a superhorizon curvaton fluctuation, then the simplest model predicts that the primordial density fluctuations…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Adrienne L. Erickcek , Christopher M. Hirata , Marc Kamionkowski

A previous work (Monteser\'in et al. 2008) estimated the CMB variance from the three-year WMAP data, finding a lower value than expected from Gaussian simulations using the WMAP best-fit cosmological model. We repeat the analysis on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 M. Cruz , P. Vielva , E. Martínez-González , R. B. Barreiro

We studied the role of fundamental constants in an updated recombination scenario, focusing on the time variation of the fine structure constant \alpha and the electron mass m_e in the early Universe. Using CMB data including WMAP 5-yr…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-02 Claudia G. Scóccola , Susana J. Landau , Hector Vucetich

We present limits to the amplitude of non-Gaussian primordial fluctuations in the WMAP 1-year cosmic microwave background sky maps. A non-linear coupling parameter, f_NL, characterizes the amplitude of a quadratic term in the primordial…

We introduce particle phenomenology on the noncommutative spacetime called the Groenewold-Moyal plane. The length scale of spcetime noncommutativity is constrained from the CPT violation measurements in $K^{0}-\bar{K}^{0}$ system and $g-2$…

High Energy Physics - Phenomenology · Physics 2009-05-22 Anosh Joseph

The recent measurements of temperature and polarization of Cosmic Microwave Background (CMB) have improved our understanding of the Universe and are in remarkable agreement with the $\Lambda$CDM cosmological model. However, scale dependent…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-15 Suvodip Mukherjee , Tarun Souradeep

We study the observational constraints of CMB temperature and polarization anisotropies on models of dark energy, with special focus on models with variation in properties of dark energy with time. We demonstrate that the key constraint…

Astrophysics · Physics 2014-10-13 H. K. Jassal , J. S. Bagla , T. Padmanabhan