Related papers: COBE-DMR constraints on the nonlinear coupling par…
We revisit the Cosmic Microwave Background (CMB) constraints on the spatial curvature of the Universe, assessing how they change when the curvature parameter and the primordial inflationary scalar spectrum are treated consistently within…
We investigate the possibility of utilising 21cm intensity mapping, optical galaxy, and Cosmic Microwave Background (CMB) surveys to constrain the power spectrum of primordial fluctuations predicted by single-field slow-roll inflation…
We combine COBE-DMR measurements of cosmic microwave background anisotropy with a recent measurement of the mass power spectrum at redshift z=2.5 from Lya forest data to derive constraints on cosmological parameters and test the…
The presence of non--Gaussian features in the Cosmic Microwave Background (CMB) radiation maps represents one of the most long--awaited clues in the search for the actual structure of the primordial radiation, still needing confirmation.…
Cosmic microwave background (CMB) temperature anisotropies follow a Gaussian statistical distribution in the standard inflationary model, but there are non-Gaussian contributions due to astrophysical foregrounds. The detection of the…
We investigate the observational signatures of three models of the early Universe in the $B$-mode polarization of the Cosmic Microwave Background (CMB) radiation. In addition to the standard single field inflationary model, we also consider…
We present a multi-class neural network (NN) classifier as a method to measure nonGaussianity, characterised by the local non-linear coupling parameter fNL, in maps of the cosmic microwave background (CMB) radiation. The classifier is…
We discuss the non-Gaussian contribution to the power spectrum covariance of cosmic microwave background (CMB) anisotropies resulting through weak gravitational lensing angular deflections and the correlation of deflections with secondary…
CDM models with non-scale-free step-like spectra of adiabatic perturbations produced in a realistic double inflationary model are compared with recent observational data. The model contains two additional free parameters relatively to the…
We point out that the inclusion of a string component contributing around 5% to the CMB power spectrum amplitude on large scales can increase the preferred value of the spectral index n_s of density fluctuations measured by CMB experiments.…
We forecast combined future constraints from the cosmic microwave background and large-scale structure on the models of primordial non-Gaussianity. We study the generalized local model of non-Gaussianity, where the parameter f_NL is…
Several recent cosmological analyses have found tension between constraints derived from the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS) data and those derived from other data sets, such as the Planck cosmic microwave…
We use quadratic maximum-likelihood (QML) estimators to constrain models with Gaussian but statistically anisotropic Cosmic Microwave Background (CMB) fluctuations, using CMB maps with realistic sky-coverage and instrumental noise. This…
In the paper we investigate observational constraints on coupling to gravity constant parameter $\xi$ using distant supernovae SNIa data, baryon oscillation peak (BOP), the cosmic microwave background radiation (CMBR) shift parameter, and…
Recent cosmic microwave background (CMB) measurements over a large range of angular scales have become sensitive enough to provide interesting constraints on cosmological parameters within a restricted class of models. We use the CMB…
We study a minimal modified gravity scenario in the symmetric teleparallel (non-metricity) formulation, focusing on an inverse non-metricity term with $f(Q)=Q+M^4 Q^{-1}$. The model does not introduce additional free parameters relative to…
We compare the predictions of hybrid inflationary models that produce both adiabatic fluctuations and topological defects to first year WMAP results. We use a Markov Chain Monte Carlo method to constrain the contribution of cosmic strings…
We look for a non-Gaussian signal in the WMAP 5-year temperature anisotropy maps by performing a needlet-based data analysis. We use the foreground-reduced maps obtained by the WMAP team through the optimal combination of the W, V and Q…
In this paper we develop a nonparametric regression method that is simultaneously adaptive over a wide range of function classes for the regression function and robust over a large collection of error distributions, including those that are…
Noncommutative inflation is based upon the consideration of some effects of the space-time uncertainty principle motivated by ideas from string/M theory. The CMB anisotropies may carry a signature of this very early Universe correction from…