English
Related papers

Related papers: Cosmic Microwave Background anisotropies and extra…

200 papers

Within a string cosmology context, the large scale temperature anisotropies may arise from the contribution of seeds to the metric fluctuations. We study the cases of electromagnetic and axion seeds. We find that massless or very light…

High Energy Physics - Phenomenology · Physics 2007-05-23 Mairi Sakellariadou

We investigate the effect of wiggly cosmic strings on the cosmic microwave background radiation anisotropy and matter power spectrum by modifying the string network model used by Albrecht et al.. We employ the wiggly equation of state for…

Astrophysics · Physics 2016-08-25 Levon Pogosian , Tanmay Vachaspati

Recently high quality data of the cosmic microwave background anisotropies have been published. In this work we study to which extent the cosmological parameters determined by using this data depend on assumptions about the initial…

Astrophysics · Physics 2009-11-06 R. Trotta , A. Riazuelo , R. Durrer

The predictions of the inflationary LCDM paradigm match today's high-precision measurements of the cosmic microwave background anisotropy extremely well. The same data put tight limits on other sources of anisotropy. Cosmic strings are a…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-29 Cora Dvorkin , Mark Wyman , Wayne Hu

We introduce a very early universe model based on the thermodynamics of a gas of closed strings in a background which is non-perturbative in $\alpha'$. Upon considering the fully $\alpha'$-corrected equations extended to include certain…

High Energy Physics - Theory · Physics 2021-03-04 Heliudson Bernardo , Robert Brandenberger , Guilherme Franzmann

Fluctuations in the temperature of the cosmic microwave background have now been detected over a wide range of angular scales, and a consistent picture seems to be emerging. This article describes some of the implications for cosmology.…

Astrophysics · Physics 2009-10-28 Douglas Scott , Joe Silk , Martin White

We review the physical processes that are thought to produce anisotropy in the cosmic microwave background, focusing primarily (but not exclusively) on the effects of acoustic waves in the early Universe. We attempt throughout to supply an…

Astrophysics · Physics 2007-05-23 Emory F. Bunn

The recent high-quality measurements of the Cosmic Microwave Background anisotropies have presented cosmologists with the possibility of studying the large scale properties of our universe with unprecedented precision. Here I review the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Alessandro Melchiorri

We present some phenomenological aspects of the pre-big-bang cosmological model inspired by the duality properties of string theory. In particular, assuming the spatial sections of the homogeneous background geometry to be isotropic, we…

Astrophysics · Physics 2012-10-23 R. Durrer , K. E. Kunze , M. Sakellariadou

We report on a current investigation of the anisotropy pattern induced by cosmic strings on the cosmic microwave background radiation (MBR). We have numerically evolved a network of cosmic strings from a redshift of $Z = 100$ to the present…

Astrophysics · Physics 2007-05-23 B. Allen , R. R. Caldwell , E. P. S. Shellard , A. Stebbins , S. Veeraraghavan

The advent of high signal-to-noise cosmic microwave background (CMB) anisotropy experiments has allowed detailed studies on the power spectrum of temperature fluctuations. The existence of acoustic oscillations in the anisotropy power…

Astrophysics · Physics 2009-11-07 Asantha Cooray

High resolution maps of the anisotropy of the microwave sky will yield invaluable clues as to the mechanisms involved in cosmic structure formation. One fundamental question they should answer is whether the fluctuations were Gaussian…

High Energy Physics - Phenomenology · Physics 2009-10-22 David Coulson , Pedro Ferreira , Paul Graham , Neil Turok

The COBE satellite's maps of the cosmic microwave background (CMB) anisotropy do not have the resolution to discriminate between theories of cosmic structure formation based on inflation, and those based on field ordering following a…

High Energy Physics - Phenomenology · Physics 2009-09-25 David Coulson , Ue-Li Pen , Neil Turok

We have investigated the cosmic microwave background (CMB) anisotropy in closed multiply connected universes (flat and hyperbolic) with low matter density. We show that the COBE constraints on these low matter density models with…

Astrophysics · Physics 2016-08-30 Kaiki Taro Inoue

We study how the presence of world-sheet currents affects the evolution of cosmic string networks, and their impact on predictions for the cosmic microwave background (CMB) anisotropies generated by these networks. We provide a general…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-21 I. Yu. Rybak , A. Avgoustidis , C. J. A. P. Martins

Inflationary string cosmology backgrounds can amplify perturbations in a more efficient way than conventional inflationary backgrounds, because the perturbation amplitude may grow - instead of being constant - outside the horizon. If not…

High Energy Physics - Theory · Physics 2007-05-23 M. Gasperini

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

Large-scale cosmic microwave background anisotropies in homogeneous, globally anisotropic cosmologies are investigated. We perform a statistical analysis in which the four-year data from the Cosmic Background Explorer satellite is searched…

Astrophysics · Physics 2008-11-26 Emory. F. Bunn , Pedro Ferreira , Joseph Silk

We combine detections of anisotropy in the Cosmic Microwave Background radiation with observations of inhomogeneity in the large-scale distribution of galaxies to test the predictions of models of cosmological structure formation. This…

Astrophysics · Physics 2009-09-25 Eric Gawiser

The spacing of the acoustic peaks in the cosmic microwave background radiation anisotropy multipole spectrum has been claimed to provide the value of the total cosmological density overtly, ``written on the sky.'' Through a semianalytic…

Astrophysics · Physics 2007-05-23 Eric V. Linder