English
Related papers

Related papers: Constraints on isocurvature models from the WMAP f…

200 papers

Compensated isocurvature perturbations (CIPs) are modulations of the relative baryon and dark matter density that leave the total matter density constant. The best current constraints from the primary cosmic microwave background (CMB) are…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-04 Selim C. Hotinli , James B. Mertens , Matthew C. Johnson , Marc Kamionkowski

Present cosmological data are well explained assuming purely adiabatic perturbations, but an admixture of isocurvature perturbations is also permitted. We use a Bayesian framework to compare the performance of cosmological models including…

We place new constraints on sources of ionizing and resonance radiation at the epoch of the recombination process using the recent CMB temperature and polarization spectra coming from WMAP. We find that non-standard recombination scenarios…

Astrophysics · Physics 2009-11-10 Rachel Bean , Alessandro Melchiorri , Joe Silk

We forecast how current ({\planck}) and future ({\prism}) cosmic microwave background (CMB) experiments constrain the adiabatic mode and its admixtures with primordial isocurvature modes, using measurements of the reconstructed CMB lensing…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Simon Muya Kasanda , Kavilan Moodley

Compensated isocurvature perturbations (CIPs) are primordial fluctuations that balance baryon and dark-matter isocurvature to leave the total matter density unperturbed. The effects of CIPs on the cosmic microwave background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-18 Tristan L. Smith , Julian B. Muñoz , Rhiannon Smith , Kyle Yee , Daniel Grin

This work presents a reduced chi^2_nu test to search for non-gaussian signals in the CMBR TT power spectrum of recent CMBR data, WMAP, ACBAR and CBI data sets, assuming a mixed density field including adiabatic and isocurvature…

Isocurvature fluctuations can be generated in various scenarios in the early Universe. In particular, some specific models predict those with a blue-tilted spectrum, which is consistent with the constraints from cosmic microwave background…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-07 Sai Chaitanya Tadepalli , Tomo Takahashi

We place functional constraints on the shape of the inflaton potential from the cosmic microwave background through a variant of the generalized slow roll approximation that allows large amplitude, rapidly changing deviations from…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-01 Cora Dvorkin , Wayne Hu

The Cosmic Microwave Background (CMB) anisotropies measurements can provide many clues about the Universe. Although the common belief is that they will allow a very precise measurement of the cosmological parameters (that is, the current…

Astrophysics · Physics 2007-05-23 Alain Riazuelo , David Langlois

Spectroscopic studies of high-redshift objects and increasingly precise data on the cosmic microwave background (CMB) are beginning to independently place strong complementary bounds on the epoch of hydrogen reionization. Parameter…

Astrophysics · Physics 2009-11-07 Aparna Venkatesan

Baryon Acoustic Oscillation (BAO) surveys will be a leading method for addressing the dark energy challenge in the next decade. We explore in detail the effect of allowing for small amplitude admixtures of general isocurvature perturbations…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 S. Muya Kasanda , C. Zunckel , K. Moodley , B. A. Bassett , P. Okouma

We study cosmological perturbations in the case that present-day matter consists of a mixture of inflaton and curvaton decay products. We calculate how the curvaton perturbations are transferred to its decay products in the general case…

Astrophysics · Physics 2007-05-23 Francesc Ferrer , Syksy Rasanen , Jussi Valiviita

We consider the most general primordial cosmological perturbation in a universe filled with photons, baryons, neutrinos, and a hypothetical cold dark matter (CDM) component within the framework of linearized perturbation theory. We give a…

Astrophysics · Physics 2009-10-31 M. Bucher , K. Moodley , N. Turok

We use a separable mode expansion estimator with WMAP data to estimate the bispectrum for all the primary families of non-Gaussian models. We review the late-time mode expansion estimator methodology which can be applied to any…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 J. R. Fergusson , M. Liguori , E. P. S. Shellard

We compare the latest cosmic microwave background data with theoretical predictions including correlated adiabatic and CDM isocurvature perturbations with a simple power-law dependence. We find that there is a degeneracy between the…

Astrophysics · Physics 2009-10-09 Luca Amendola , Christopher Gordon , David Wands , Misao Sasaki

If low-energy SUSY exists, LHC data favors a high mass scale for scalar superpartners (above a TeV), while sfermions and the dark matter can be parametrically lighter -- leading to a so-called split-spectrum. When combining this fact with…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-03 Luca Iliesiu , David J. E. Marsh , Kavilan Moodley , Scott Watson

We use observations of cosmic microwave background anisotropies, supernova luminosities and the baryon acoustic oscillation signal in the galaxy distribution to constrain the cosmological parameters in a simple interacting dark energy model…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-18 Jussi Valiviita , Roy Maartens , Elisabetta Majerotto

(Abridged) The WMAP 5-year data strongly limit deviations from the minimal LCDM model. We constrain the physics of inflation via Gaussianity, adiabaticity, the power spectrum shape, gravitational waves, and spatial curvature. We also…

A linear modulation of the primordial perturbations is proposed as an explanation for the observed asymmetry between the northern and southern hemispheres of the Wilkinson Microwave Anisotropy Probe (WMAP) data. A cut sky, reduced…

Astrophysics · Physics 2008-11-26 Christopher Gordon

We outline the expected constraints on non-Gaussianity from the cosmic microwave background (CMB) with current and future experiments, focusing on both the third (f_{NL}) and fourth-order (g_{NL} and \tau_{NL}) amplitudes of the local…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-27 Joseph Smidt , Alexandre Amblard , Christian T. Byrnes , Asantha Cooray , Alan Heavens , Dipak Munshi