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Related papers: Constraints on isocurvature models from the WMAP f…

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We report the constraints of $H_0$ obtained from Wilkinson Microwave Anisotropy Probe (WMAP) combined with the latest baryonic acoustic oscillations (BAO) measurements. We use the BAO measurements from the 6dF Galaxy Survey (6dFGS), the…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-06 Xue Zhang , Qing-Guo Huang

We study how to set the initial evolution of general cosmological fluctuations at second order, after neutrino decoupling. We compute approximate initial solutions for the transfer functions of all the relevant cosmological variables…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-22 Pedro Carrilho , Karim A. Malik

Recently, two issues concerning the three-year WMAP likelihood code were pointed out. On large angular scales ($l \lesssim 30$), a sub-optimal likelihood approximation resulted in a small power excess. On small angular scales ($l \gtrsim…

Astrophysics · Physics 2007-05-23 Jostein R. Kristiansen , Hans Kristian Eriksen , Oystein Elgaroy

We present full sky microwave maps in five bands (23 to 94 GHz) from the WMAP first year sky survey. Calibration errors are <0.5% and the low systematic error level is well specified. The 2<l<900 anisotropy power spectrum is cosmic variance…

Dark matter comprised of axion-like particles (ALPs) generated by the realignment mechanism in the post-inflationary scenario leads to primordial isocurvature fluctuations. The power spectrum of these fluctuations is flat for small wave…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-09 Martin Feix , Steffen Hagstotz , Andreas Pargner , Robert Reischke , Bjoern Malte Schaefer , Thomas Schwetz

In the curvaton scenario, primordial curvature perturbations are produced by a second field that is sub-dominant during inflation. Depending on how the curvaton decays [possibly producing baryon number, lepton number, or cold dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-23 Tristan L. Smith , Daniel Grin

We present constraints on the extended Starobinsky and Weyl gravity model of inflation using updated available observational data. The data includes cosmic microwave background (CMB) anisotropy measurements from Planck and BICEP/Keck 2018…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-22 Piyabut Burikham , Teeraparb Chantavat , Pongsapat Boonaom

We describe the calibration and data processing methods used to generate full-sky maps of the cosmic microwave background (CMB) from the first year of Wilkinson Microwave Anisotropy Probe (WMAP) observations. Detailed limits on residual…

Using the covariant formalism developed in a companion paper (paper I), we derive observational constraint on the Brans-Dicke model in a flat FLRW universe with cosmological constant and cold dark matter. The CMB observations we use include…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Fengquan Wu , Xuelei Chen

We apply the Gabor transform methodology proposed in (Hansen et al. 2002, 2003) to the WMAP data in order to test the statistical properties of the CMB fluctuation field and specifically to evaluate the fundamental assumption of…

Astrophysics · Physics 2009-05-29 F. K. Hansen , A. J. Banday , K. M. Gorski

We use quadratic maximum-likelihood (QML) estimators to constrain models with Gaussian but statistically anisotropic Cosmic Microwave Background (CMB) fluctuations, using CMB maps with realistic sky-coverage and instrumental noise. This…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-06 Duncan Hanson , Antony Lewis

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

Astrophysics · Physics 2009-11-11 Tarun Souradeep , Amir Hajian , Soumen Basak

The Cosmic Microwave Background (CMB) anisotropy constrains the geometry of the Universe because the positions of the acoustic peaks of the angular power spectrum depend strongly on the curvature of underlying three-dimensional space. In…

Astrophysics · Physics 2009-11-13 J. Dunkley , M. Bucher , P. G. Ferreira , K. Moodley , C. Skordis

We investigate the effects of isocurvature perturbations on the 21cm radiation from minihaloes (MHs) at high redshifts and examine constraints on the isocurvature amplitude and power spectrum using the next generation of radio telescopes…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 Yoshitaka Takeuchi , Sirichai Chongchitnan

The existence of dark radiation that is completely decoupled from the standard model in the early Universe leaves open the possibility of an associated dark radiation isocurvature mode. We show that the presence of dark radiation…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-12 Peter Adshead , Gilbert Holder , Pranjal Ralegankar

In this paper we study the isocurvature mode contribution to the cosmic microwave background anisotropies and the large scale structure power spectrum, for a two-field model of inflation proposed by Linde and Mukhanov. We provide…

High Energy Physics - Phenomenology · Physics 2008-11-26 Elena Pierpaoli , Juan Garcia-Bellido , Stefano Borgani

We constrain the form of the primordial power spectrum using Wilkinson Microwave Anisotropy Probe (WMAP) 3-year cosmic microwave background (CMB) data (+ other high resolution CMB experiments) in addition to complementary large-scale…

Astrophysics · Physics 2009-11-11 M. Bridges , A. N. Lasenby , M. P. Hobson

Over the next decade, improvements in cosmological parameter constraints will be driven by surveys of large-scale structure. Its inherent non-linearity suggests that significant information will be embedded in higher correlations beyond the…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Joyce Byun , Alexander Eggemeier , Donough Regan , David Seery , Robert E. Smith

We compare and combine likelihood functions of the cosmological parameters Omega_m, h and sigma_8 from the CMB, type Ia supernovae and from probes of large scale structure. We include the recent results from the CMB experiments BOOMERANG…

Astrophysics · Physics 2007-05-23 S. L. Bridle