Related papers: Is $\Lambda$CDM on the run? Reconciling the CMB wi…
We present the first attempt to use a combination of CMB, LIGO, and PPTA data to constrain both the tilt and the running of primordial tensor power spectrum through constraints on the gravitational wave energy density generated in the early…
We build an inflationary model based on Degenerate Higher Order Scalar Tensor (DHOST) theories in a de Sitter background. We determine the scale-dependent power spectrum of curvature perturbations in these theories and we show that such a…
Cosmological $\alpha$-attractors are a compelling class of inflationary models. They lead to universal predictions for large-scale observables, broadly independent from the functional form of the inflaton potential. In this work we derive…
We present the first direct constraints on a Degenerate Higher Order Scalar Tensor (DHOST) inflation model using the Planck 2018 Cosmic Microwave Background (CMB) results on non-Gaussianities. We identify that the bispectrum consists of a…
Amongst the multitude of inflationary models currently available, models that lead to features in the primordial scalar spectrum are drawing increasing attention, since certain features have been found to provide a better fit to the CMB…
The newly released Planck CMB data place tight constraints on slow-roll inflationary models. Some of commonly discussed inflationary potentials are disfavored due mainly to the large tensor-to-scalar ratio. In this paper we show that these…
We develop an accurate and efficient Bayesian method to reconstruct the primordial power spectrum in a model-independent way, and apply it to the latest cosmic microwave background measurement from Planck mission, and the large scale…
We present a semi--analytic exploration of some low--$\ell$ angular power spectra inspired by "Brane Supersymmetry Breaking". This mechanism splits Bose and Fermi excitations in String Theory, leaving behind an exponential potential that is…
This paper presents the Planck 2015 likelihoods, statistical descriptions of the 2-point correlations of CMB data, using the hybrid approach employed previously: pixel-based at $\ell<30$ and a Gaussian approximation to the distribution of…
Considerable and ongoing effort is made to identify promising scalar field candidates in string theory to drive a cosmological period of inflation. At stake is the possibility that fundamental string parameters could be encoded in…
We address the possibility of bounding the spectral index $n$ of primordial density fluctuations, using both the cosmic microwave background (cmb) anisotropy and data on galaxies and clusters. Each piece of galaxy and cluster data is…
In the light of the recent Boomerang and Maxima observations of the CMB which show an anomalously low second acoustic peak, we reexamine the prediction by Adams et al (1997) that this would be the consequence of a 'step' in the primordial…
String Theory and Supergravity allow, in principle, to follow the transition of the inflaton from pre-inflationary fast roll to slow roll. This introduces an infrared depression in the primordial power spectrum that might have left an…
The recent Planck data on the power spectrum of temperature anisotropies of the cosmic microwave background marginally support deviations from the $\Lambda$CDM model at several multipoles. With a view towards current and forthcoming…
Measuring spectral distortions (SDs) of the cosmic microwave background (CMB) will provide new constraints on previously unexplored scales of the primordial power spectrum, allowing us to extend the probed parameter space by several orders…
We provide the latest constraints on the power spectra of both scalar and tensor perturbations from the CMB data (including \textit{Planck}~2015, BICEP2 \& \textit{Keck Array} experiments) and the new BAO scales from SDSS-III BOSS…
Primordial magnetic fields can change the recombination history of the universe by inducing clumping in the baryon density at small scales. They were recently proposed as a candidate model to relieve the Hubble tension. We investigate the…
[Abridged] A sharp cut-off in the primordial scalar power spectrum on large scales has been known to improve the fit to the cosmic microwave background (CMB) data when compared to the more standard, nearly scale invariant power spectrum…
We obtain cosmological constraints on models of inflation which exhibit rapid roll solutions. Rapid roll attractors exist for potentials with large mass terms and are thus of interest for inflationary model building within string theory. We…
We investigate inflationary scenarios driven by a class of potentials which are similar in form to those that arise in certain minimal supersymmetric extensions of the standard model. We find that these potentials allow a brief period of…