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Related papers: Non-Random Phases in Non-Trivial Topologies

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A number of theoretically well-motivated additions to the standard cosmological model predict weak signatures in the form of spatially localized sources embedded in the cosmic microwave background (CMB) fluctuations. We present a…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-18 Stephen M. Feeney , Matthew C. Johnson , Jason D. McEwen , Daniel J. Mortlock , Hiranya V. Peiris

The shortest distance around the Universe through us is unlikely to be much larger than the horizon diameter if microwave background anomalies are due to cosmic topology. We show that observational constraints from the lack of matched…

Cosmic microwave background (CMB) temperature and polarization observations indicate that in the best-fit $\Lambda$ Cold Dark Matter model of the Universe, the local geometry is consistent with at most a small amount of positive or negative…

We study a specific correlation in spherical harmonic multipole domain for cosmic microwave background (CMB) analysis. This group of correlation between \Delta l=4n, n=1,2... is caused by symmetric signal in the Galactic coordinate system.…

Astrophysics · Physics 2009-11-13 Pavel D. Naselsky , Igor D. Novikov , Lung-Yih Chiang

CMB anisotropy data could put powerful constraints on theories of the evolution of our Universe. Using the observations of the large number of CMB experiments, many studies have put constraints on cosmological parameters assuming different…

Astrophysics · Physics 2015-06-24 Marian Douspis

Geometry constrains but does not dictate the topology of the 3--dimensional space. In a locally spatially homogeneous and isotropic universe, however, the topology of its spatial section dictates its geometry. We show that, besides…

Astrophysics · Physics 2009-11-11 M. J. Reboucas , J. S. Alcaniz

Planck's Cosmic Microwave Background temperature and polarization observations are the premier dataset for constraining cosmological models. Cosmic variance limited temperature at large and intermediate scales today dominates the…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-18 Adrien La Posta , Umberto Natale , Erminia Calabrese , Xavier Garrido , Thibaut Louis

Large patterns could exist on the microwave sky as a result of various non-standard possibilities for the large-scale Universe -- rotation or shear, non-trivial topology, and single topological defects are specific examples. All-sky (or…

Astrophysics · Physics 2009-10-31 Emory F. Bunn , Douglas Scott

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

The cross-correlation between the cosmic microwave background (CMB) fields and matter tracers carries important cosmological information. In this paper, we forecast by a signal-to-noise ratio analysis the information contained in the…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-10 José R. Bermejo-Climent , Mario Ballardini , Fabio Finelli , Daniela Paoletti , Roy Maartens , José A. Rubiño-Martin , Luca Valenziano

We propose an efficient Bayesian MCMC algorithm for estimating cosmological parameters from CMB data without use of likelihood approximations. It builds on a previously developed Gibbs sampling framework that allows for exploration of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-29 Benjamin Racine , Jeffrey B. Jewell , Hans Kristian K. Eriksen , Ingunn K. Wehus

A new analysis of the CMB, using WMAP data, supports earlier indications of non-Gaussian features of concentric circles of low temperature variance. Conformal cyclic cosmology (CCC) predicts such features from supermassive black-hole…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-06 V. G. Gurzadyan , R. Penrose

The era of precision cosmology has allowed us to accurately determine many important cosmological parameters, in particular via the CMB. Confronting Loop Quantum Cosmology with these observations provides us with a powerful test of the…

General Relativity and Quantum Cosmology · Physics 2012-04-06 Ivan Agullo , Abhay Ashtekar , William Nelson

Unexpected features have been observed in the cosmic microwave background (CMB) temperature on large scales. We revisit these CMB anomalies using new foreground-cleaned CMB temperature maps derived in a companion paper from WMAP and Planck…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-05 Laura Herold , Graeme E. Addison , Charles L. Bennett , Hayley C. Nofi , J. L. Weiland

We present an analysis of the phase space of cosmological models based on a non minimal coupling between the geometry and a fermionic condensate. We obtain that the strong constraint coming from the Dirac equations allows a detailed design…

General Relativity and Quantum Cosmology · Physics 2018-04-20 Sante Carloni , Stefano Vignolo , Roberto Cianci

We reexamine interactions between the dark sectors of cosmology, with a focus on robust constraints that can be obtained using only mildly nonlinear scales. While it is well known that couplings between dark matter and dark energy can be…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-18 V Miranda , Mariana Carrillo González , Elisabeth Krause , Mark Trodden

A new method for analyzing point patterns produced by the evolution of gravitational clustering is presented. The method is taken from the study of molecular liquids, where it has been introduced for making a statistical description of…

Astrophysics · Physics 2009-10-31 R. Valdarnini

In this talk I propose the first fast methods which can analyze CMB data taking into account correlated noise, arbitrary beam shapes, non-uniform distribution of integration time on the sky, and partial sky coverage, without the need for…

Astrophysics · Physics 2007-05-23 Benjamin D. Wandelt

We present a framework for cosmological model selection using Neural Networks (NNs) trained directly on simulated Cosmic Microwave Background (CMB) temperature and polarisation maps. By operating at the map level rather than on compressed…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-08 Indira Ocampo , Guadalupe Cañas-Herrera

The Universe is not perfectly homogeneous, the large scale structure forms overdense regions and voids. In this paper, we consider the possibility that we occupy a special position in our Universe, close to the center of a local underdense…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-13 Viraj Nistane , Giulia Cusin , Martin Kunz
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