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Related papers: A Counterexample to Claimed COBE Constraints on Co…

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Full suite of the present day Cosmic Microwave background (CMB) data, when combined with weak prior information on the Hubble constant and the age of the Universe, or the Large-Scale structure, provides strong indication for a non-zero…

Astrophysics · Physics 2007-05-23 D. Pogosyan , J. R. Bond , C. R. Contaldi

The near-isotropy of the cosmic microwave background (CMB) is considered to be the strongest indication for the homogeneity and isotropy of the universe, a cornerstone of most cosmological analysis. We derive new theorems which extend the…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-09 Syksy Rasanen

We consider a universe with a non-classical stringy topology that has fixed points. We concentrate on the simplest example, an orbifold point, and study its observable imprints on the cosmic microwave background (CMB). We show that an…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-21 Assaf Ben-David , Ben Rathaus , Nissan Itzhaki

Cosmological models where the standard big bang is replaced by a bounce have been studied for decades. The situation has, however, dramatically changed in the past years for two reasons: first, because new ways to probe the early Universe…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-17 J. Grain , A. Barrau , T. Cailleteau , J. Mielczarek

Several cosmological measurements have attained significant levels of maturity and accuracy over the last decade. Continuing this trend, future observations promise measurements of the statistics of the cosmic mass distribution at an…

Astrophysics · Physics 2008-11-26 Salman Habib , Katrin Heitmann , David Higdon , Charles Nakhleh , Brian Williams

A simple and surprisingly realistic model of the origin of the universe can be developed using the Friedmann equation from general relativity, elementary quantum mechanics, and the experimental values of h, c, G and the proton mass. The…

General Relativity and Quantum Cosmology · Physics 2015-06-25 T. R. Mongan

The semi-classical approach to the quantum geometrodynamical model is used for the description of the properties of the universe on extremely small spacetime scales. Quantum theory for a homogeneous, isotropic and closed universe is…

General Relativity and Quantum Cosmology · Physics 2009-10-21 V. E. Kuzmichev , V. V. Kuzmichev

It is predicted that the spectrum of radio emission from the whole sky should show a dip arising from the action of the light from the first stars on the hydrogen atoms in the surrounding gas, which causes the 21-cm line to appear in…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-27 Richard Hills , Girish Kulkarni , P. Daniel Meerburg , Ewald Puchwein

The map-making process of Cosmic Microwave Background data involves linear inversion problems which cannot be performed by a brute force approach for the large timelines of most modern experiments. We present optimal iterative map-making…

Astrophysics · Physics 2010-12-13 Xavier Dupac

Using a simple analytic model based on seed superposition we obtain the spectrum of microwave background perturbations induced by cosmic strings on all angular scales larger than about 2 armin. We assume standard recombination in an…

Astrophysics · Physics 2011-05-10 Leandros Perivolaropoulos

Our current description of the large-scale Universe is now known with a precision undreamt of a generation ago. Within the simple standard cosmological model only six basic parameters are required. The usual parameter set includes…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-30 Douglas Scott , Ali Narimani , Don N. Page

Inspired by the entropy-area relation of black hole thermodynamics, we study the thermodynamics of cosmological apparent horizon in a spatially flat Friedmann-Robertson-Walker (FRW) universe in the framework of an Extended Uncertainty…

General Relativity and Quantum Cosmology · Physics 2024-08-29 Maryam Roushan , Narges Rashidi , Kourosh Nozari

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

We investigate in detail the question whether a non-vanishing cosmological constant is required by present-day cosmic microwave background and large scale structure data when general isocurvature initial conditions are allowed for. We also…

Astrophysics · Physics 2007-07-23 R. Trotta , A. Riazuelo , R. Durrer

We have refined the analysis of the data from the FIRAS (Far InfraRed Absolute Spectrophotometer) on board the COBE (COsmic Background Explorer). The FIRAS measures the difference between the cosmic microwave background and a precise…

Astrophysics · Physics 2009-10-28 D. J. Fixsen , E. S. Cheng , J. M. Gales , J. C. Mather , R. A. Shafer , E. L. Wright

Recently funded satellites will map the cosmic microwave background radiation with unprecedented sensitivities and angular resolutions. Assuming only primordial adiabatic scalar and tensor perturbations, we evaluate how accurately…

Astrophysics · Physics 2009-10-28 Arthur Kosowsky , Marc Kamionkowski , Gerard Jungman , David N. Spergel

The ARCADE2 and LWA1 experiments have claimed an excess over the Cosmic Microwave Background (CMB) at low radio frequencies. If the cosmological high-redshift contribution to this radio background is between 0.1% and 22% of the CMB at 1.42…

We describe the first instrument of a Cosmic Microwave Background experiment for mapping cosmological structures on medium angular scales (the COSMOSOMAS experiment) and diffuse Galactic emission. The instrument is located at Teide…

The precision cosmological model describing the origin and expansion history of the universe, with observed structure seeded at the inflationary cosmic horizon, demands completion in the ultraviolet and in the infrared. The dynamics of the…

High Energy Physics - Theory · Physics 2022-03-16 Raphael Flauger , Victor Gorbenko , Austin Joyce , Liam McAllister , Gary Shiu , Eva Silverstein

We present a novel test of the cosmological principle: the idea that, on sufficiently large scales, the universe should appear homogeneous and isotropic to observers comoving with the Hubble flow. This is a fundamental assumption in modern…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-19 Oliver T. Oayda , Geraint F. Lewis
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