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WMAP precision data enables accurate testing of cosmological models. We find that the emerging standard model of cosmology, a flat Lambda-dominated universe seeded by nearly scale-invariant adiabatic Gaussian fluctuations, fits the WMAP…

While the observed nearly scale-invariant initial power spectrum is regarded as one of the favorable evidence of the standard inflationary cosmology, precision observations of the Cosmic Microwave Background (CMB) anisotropies also suggest…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-06 Koichiro Horiguchi , Kiyotomo Ichiki , Jun'ichi Yokoyama

We use WMAP 9-year and other CMB data to constrain cosmological models where the primordial perturbations have both an adiabatic and a (possibly correlated) neutrino density (NDI), neutrino velocity (NVI), or cold dark matter density (CDI)…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-30 Matti Savelainen , Jussi Valiviita , Parampreet Walia , Stanislav Rusak , Hannu Kurki-Suonio

Cosmological inflation and topological defects have been considered for a long time, either in disagreement or in competition. On the one hand an inflationary era is required to solve the shortcomings of the hot big bang model, while on the…

High Energy Physics - Theory · Physics 2008-11-26 Mairi Sakellariadou

Thawing quintessence scalar field models with the various potential forms to explain the late-time cosmic acceleration are compared to the {\Lambda}CDM model in detail by analyzing cosmological parameters with a set of observational data…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-11 Fereshteh Felegary , Kazuharu Bamba

We explore constraints on various forms for the effective potential during inflation based upon a statistical comparison between inflation-generated fluctuations in the cosmic microwave background temperature and the COBE DMR results. Fits…

Astrophysics · Physics 2009-10-22 Hannu Kurki-Suonio , Grant J. Mathews

The cosmic microwave background (CMB) is a unique probe of cosmological parameters and conditions. There is a connection between anisotropy in the CMB and the topology of the Universe. Adopting a universe with the topology of a 3-Torus, or…

Astrophysics · Physics 2009-10-22 Angelica de Oliveira-Costa , George F. Smoot

With the WMAP data we can now begin to test realistic models of inflation involving multiple scalar fields. These naturally lead to correlated adiabatic and isocurvature (entropy) perturbations with a running spectral index. We present the…

Astrophysics · Physics 2011-07-19 David Parkinson , Shinji Tsujikawa , Bruce A. Bassett , Luca Amendola

The exact nature of dark energy is currently unknown and its cosmological perturbations, when dark energy is assumed not to be the cosmological constant, are usually modeled as adiabatic. Here we explore the possibility that dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-23 Rubén Arjona , Juan García-Bellido , Savvas Nesseris

Cosmic strings generate vector and tensor modes in the B-channel of polarization, as well as the usual temperature power spectrum and E-mode polarization spectrum. We use the power spectrum obtained from high-resolution Nambu-Goto cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-25 Andrei Lazanu , E. P. S. Shellard

%The content of this replacement paper is identical to the original. %We have attempted to fix the postscript so that it will print out on %a larger number of printers. Using recent experimental limits on $\mu$ distortions from COBE FIRAS,…

Astrophysics · Physics 2009-10-22 Wayne Hu , Douglas Scott , Joseph Silk

High-significance measurements of the monopole thermal Sunyaev-Zel'dovich CMB spectral distortions have the potential to tightly constrain poorly understood baryonic feedback processes. The sky-averaged Compton-y distortion and its…

The WMAP team has recently highlighted the usefulness of combining the Ly-alpha forest constraints with those from the cosmic microwave background (CMB). This combination is particularly powerful as a probe of the primordial shape of the…

Astrophysics · Physics 2009-11-07 Uros Seljak , Patrick McDonald , Alexey Makarov

We present constraints on the amplitude of matter fluctuations from the clustering of galaxies and their cross-correlation with the gravitational lensing convergence of the cosmic microwave background (CMB), focusing on low redshifts…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-13 Andrea Rubiola , Matteo Zennaro , Carlos García-García , David Alonso

The cosmic microwave background (CMB) temperature autocorrelations, induced by a magnetized adiabatic mode of curvature inhomogeneities, are computed with semi-analytical methods. As suggested by the latest CMB data, a nearly…

Astrophysics · Physics 2008-11-26 Massimo Giovannini

We present the first complete Markov chain Monte Carlo analysis of cosmological models with evolving cosmic (super)string networks, using the unconnected segment model in the unequal-time correlator formalism. For ordinary cosmic string…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-08 Tom Charnock , Anastasios Avgoustidis , Edmund J. Copeland , Adam Moss

Inflation in a five-dimensional brane world model with two boundary branes is studied. We make use of the moduli space approximation whereby the low energy theory reduces to a four-dimensional biscalar-tensor gravity plus a minimally…

(abridged) We explore the statistical properties of non-linear cosmic structures in a flat $\Lambda$CDM cosmology in which the index of the primordial power spectrum for scalar perturbations is allowed to depend on the scale. Within the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 C. Fedeli , F. Finelli , L. Moscardini

We use the WMAP 7 data to place constraints on oscillations supplementing an almost scale-invariant primordial power spectrum. Such oscillations are predicted by a variety of models, some of which amount to assuming there is some…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 P. Daniel Meerburg , Ralph Wijers , Jan Pieter van der Schaar

We present constraints on a cosmic string network with a measurement of weak gravitational lensing from CMB temperature map. The cosmic string network between observer and last scattering surface of CMB photons generates vector and/or…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Toshiya Namikawa , Daisuke Yamauchi , Atsushi Taruya