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Related papers: Microwave Background Fluctuations in an Open Unive…

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In this work, we analyse the temperature fluctuations of the cosmic microwave background radiation observed by COBE and show that the distribution can be fitted by a fractal distribution with a fractal dimension $ D= 1.43 \pm 0.07 $. This…

The cosmic microwave anisotropies in a scenario of large scale structure formation with cold dark matter and texture are discussed and compared with recent observational results of the COBE satellite. A couple of important statistical…

Astrophysics · Physics 2008-11-26 R. Durrer , A. Howard , Z. -H. Zhou

We investigate cosmological structure formation seeded by topological defects which may form during a phase transition in the early universe. First we derive a partially new, local and gauge invariant system of perturbation equations to…

Astrophysics · Physics 2009-10-28 R. Durrer , Z. -H. Zhou

Variations in $\Omega$, the total density of the Universe, leave a clear and distinctive imprint on the power spectrum of temperature fluctuations in the cosmic microwave background (CMB). This signature is virtually independent of other…

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

The power spectrum of fluctuations in the cosmic microwave background (CMB) depends on most of the key cosmological parameters. Accurate future measurements of this power spectrum might therefore allow us to determine h, Omega, Omega_b,…

Astrophysics · Physics 2007-05-23 Max Tegmark

We investigate the potential of observations of anisotropies in the cosmic microwave background (CMB) and large-scale structure in the Universe to detect possible modifications of standard inflationary models by physics beyond the Planck…

Astrophysics · Physics 2009-11-10 Oystein Elgaroy , Steen Hannestad

We calculate predictions from defect models of structure formation for both the matter and Cosmic Microwave Background (CMB) over all observable scales. Our results point to a serious problem reconciling the observed large-scale galaxy…

Astrophysics · Physics 2010-04-08 Andreas Albrecht , Richard A. Battye , James Robinson

We study the Cosmic Microwave Background (CMB) anisotropies produced by cosine-type quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into account. For purely adiabatic fluctuations…

Astrophysics · Physics 2007-05-23 Tomo Takahashi

The shape of the primordial fluctuation spectrum is probed by cosmic microwave background fluctuations which measure density fluctuations at z~1000 on scales of hundreds of Mpc and from galaxy redshift surveys, which measure structure at…

Astrophysics · Physics 2014-10-13 Joseph Silk , Eric Gawiser

The Cosmic Microwave Background (CMB), which permeates the entire Universe, is the radiation left over from just 380,000 years after the Big Bang. On very large scales, the CMB radiation field is smooth and isotropic, but the existence of…

We calculate the spectrum of large angle cosmic microwave background (CMB) anisotropies due to quantum fluctuations of the gravitational wave modes in one-bubble open inflation models. We find the bubble-wall fluctuation modes, which had…

Astrophysics · Physics 2016-08-30 Misao Sasaki , Takahiro Tanaka , Yoshihiro Yakushige

We argue that the observed large-scale cosmic microwave anomalies, discovered by WMAP and confirmed by the Planck satellite, are most naturally explained in the context of a marginally-open universe. Particular focus is placed on the dipole…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-05 Andrew R Liddle , Marina Cortês

Recent measurements of the cosmic microwave background (CMB) anisotropies by BOOMERANG and MAXIMA collaborations have tightened the observational constraints on theories of structure formation. They disagree with the predictions of…

Astrophysics · Physics 2009-10-31 Levon Pogosian

We investigate the global texture model of structure formation in cosmogonies with non-zero cosmological constant for different values of the Hubble parameter. We find that the absence of significant acoustic peaks and little power on large…

Astrophysics · Physics 2009-10-31 Ruth Durrer , Martin Kunz , Alessandro Melchiorri

Skewness of temperature fluctuations of the cosmic microwave background (CMB) produced by initially Gaussian adiabatic perturbations with the flat (Harrison-Zeldovich) spectrum, which arises due to non-linear corrections to a gravitational…

Astrophysics · Physics 2009-10-28 Dipak Munshi , Tarun Souradeep , Alexei A. Starobinsky

We present the results of analysis of constraints on cosmological parameters from cosmic microwave background (CMB) alone and in combination with galaxy cluster baryon fraction assuming inflation--generated adiabatic scalar fluctuations.…

Astrophysics · Physics 2009-11-06 M. Douspis , A. Blanchard , R. Sadat , J. G. Bartlett , M. Le Dour

We study the topology generated by the temperature fluctuations of the Cosmic Microwave Background (CMB) radiation, as quantified by the number of components and holes, formally given by the Betti numbers, in the growing excursion sets. We…

We study the Cosmic Microwave Background (CMB) anisotropies produced by cosine-type quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into account. For purely adiabatic fluctuations…

Astrophysics · Physics 2009-11-06 Masahiro Kawasaki , Takeo Moroi , Tomo Takahashi

We point out that the temperature fluctuations of cosmic microwave background (CMB) can be generated in a way that is different from the one usually assumed in slow-roll inflation. Our mechanism is based on vacuum fluctuations of fields…

High Energy Physics - Theory · Physics 2012-05-18 Yoshinobu Habara , Hikaru Kawai , Masao Ninomiya , Yasuhiro Sekino

We cross correlate the large-scale cosmic microwave background (CMB) sky measured by WMAP with two probes of large-scale structure at z ~ 1. The hard X-ray background, measured by the HEAO-1 satellite, is positively correlated with the WMAP…

Astrophysics · Physics 2008-11-26 Stephen Boughn , Robert Crittenden