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We generalize the predictions for the CMB anisotropy patterns arising in Bianchi type VIIh universes to include a dark energy component. We consider these models in light of the result of Jaffe et al. (2005a,b) in which a correlation was…

Astrophysics · Physics 2009-11-13 T. R. Jaffe , S. Hervik , A. J. Banday , K. M. Gorski

Bianchi VII_h models have been recently proposed to explain potential anomalies in the CMB anisotropy as observed by WMAP. We investigate the violation of statistical isotropy due to an embedded Bianchi VII_h templates in the CMB anisotropy…

Astrophysics · Physics 2008-11-26 Tuhin Ghosh , Amir Hajian , Tarun Souradeep

We perform a definitive analysis of Bianchi VII_h cosmologies with WMAP observations of the cosmic microwave background (CMB) temperature anisotropies. Bayesian analysis techniques are developed to study anisotropic cosmologies using…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-04 J. D. McEwen , T. Josset , S. M. Feeney , H. V. Peiris , A. N. Lasenby

We describe our methodology for comparing the WMAP measurements of the cosmic microwave background (CMB) and other complementary data sets to theoretical models. The unprecedented quality of the WMAP data, and the tight constraints on…

We study the Bianchi-I cosmological model motivated by signals of statistical isotropy violation seen in cosmic microwave background (CMB) observations and others. To that end, we consider various kinds of anisotropic matter that source…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Anshul Verma , Sanjeet K. Patel , Pavan K. Aluri , Sukanta Panda , David F. Mota

We use recent 36 observational Hubble data (OHD) in the redshift range $0.07\leq z\leq 2.36$, latest \textgravedbl joint light curves\textacutedbl (JLA) sample, comprised of 740 type Ia supernovae (SNIa) in the redshift range $0.01\leq z…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-21 H. Amirhashchi , S. Amirhashchi

Motivated by the success of the Bianchi VII_h model in addressing many of the anomalies observed in the WMAP data (Jaffe et al.), we present calculations in real and in wavelet space of the Higher Criticism statistic of the Bianchi…

Astrophysics · Physics 2009-11-11 L. Cayon , A. J. Banday , T. Jaffe , H. K. Eriksen , F. K. Hansen , K. M. Gorski , J. Jin

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

The first-year WMAP data, in combination with any one of a number of other cosmic probes, show that we live in a flat \Lambda-dominated CDM universe with \Omega_m ~ 0.27 and \Omega_\Lambda ~ 0.73. In this model the late-time action of the…

We determine the range of parameter space of Interacting Quintessence Models that best fits the recent WMAP measurements of Cosmic Microwave Background temperature anisotropies. We only consider cosmological models with zero spatial…

Astrophysics · Physics 2009-11-10 German Olivares , Fernando Atrio-Barandela , Diego Pavon

We present a new estimate of foreground emission in the WMAP data, using a Markov chain Monte Carlo (MCMC) method. The new technique delivers maps of each foreground component for a variety of foreground models, error estimates of the…

We derive the CMB radiative transfer equation in the form of a multipole hierarchy in the nearly-Friedmann-Robertson-Walker limit of homogeneous, but anisotropic, universes classified via their Bianchi type. Compared with previous…

Astrophysics · Physics 2007-09-13 Andrew Pontzen , Anthony Challinor

Motivated by the large-scale asymmetry observed in the cosmic microwave background sky, we consider a specific class of anisotropic cosmological models -- Bianchi type VII_h -- and compare them to the WMAP first-year data on large angular…

Astrophysics · Physics 2009-11-10 T. R. Jaffe , A. J. Banday , H. K. Eriksen , K. M. Gorski , F. K. Hansen

In this letter, we report the observational constraints on a Bianchi type I anisotropic extension of $w$CDM model with spatial curvature from observational data including Baryon Acoustic Oscillations (BAO), Cosmic chronometers (CC), Big…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-21 Vikrant Yadav , Rajpal , Pardeep , Manish Yadav , Santosh Kumar Yadav

We perform a detailed comparison of the Wilkinson Microwave Anisotropy Probe (WMAP) measurements of the cosmic microwave background (CMB) temperature and polarization anisotropy with the predictions of quintessence cosmological models of…

Astrophysics · Physics 2009-11-07 Robert R. Caldwell , Michael Doran

We search for the presence of cosmological neutrino background (CNB) anisotropies in recent WMAP 5-year data using their signature imprinted on modifications to cosmic microwave background (CMB) anisotropy power spectrum. By parametrizing…

In the current study, we present the observational data constraints on the parameters space for an anisotropic cosmological model of Bianchi I type spacetime in general relativity (GR). For the analysis, we consider observational datasets…

General Relativity and Quantum Cosmology · Physics 2025-07-31 Vinod Kumar Bhardwaj , Manish Kalra , Priyanka Garg , Saibal Ray

We present a new framework for testing the isotropy of the Universe using cosmic microwave background data, building on the nested-sampling ANICOSMO code. Uniquely, we are able to constrain the scalar, vector and tensor degrees of freedom…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-08 Daniela Saadeh , Stephen M. Feeney , Andrew Pontzen , Hiranya V. Peiris , Jason D. McEwen

We present the temperature and polarization angular power spectra of the cosmic microwave background (CMB) derived from the first 5 years of WMAP data. The 5-year temperature (TT) spectrum is cosmic variance limited up to multipole l=530,…

We compute the cosmic microwave background (CMB) anisotropy in a low-density, flat, cosmological constant, cold dark matter model which is normalized to the two-year COBE DMR sky map. Although conclusions regarding model viability must…

Astrophysics · Physics 2015-06-24 Bharat Ratra , Naoshi Sugiyama
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