Search Publications
µ distortions or running: A guaranteed discovery from CMB spectrometry
Melchiorri, Alessandro; Cabass, Giovanni; Pajer, Enrico
We discuss the implications of a PIXIE-like experiment, which would measure µ -type spectral distortions of the cosmic microwave background (CMB) at a level of σµ=(1 /n )×10-8 , with n ≥1 representing an improved sensitivity (e.g. n =10 corresponds to PRISM). Using Planck data and considering the six-parameter Λ C…
Constraints on the running of the running of the scalar tilt from CMB anisotropies and spectral distortions
Di Valentino, Eleonora; Melchiorri, Alessandro; Cabass, Giovanni +2 more
We use the recent observations of cosmic microwave background (CMB) temperature and polarization anisotropies provided by the Planck satellite experiment to place constraints on the running αs=d ns/d log k and the running of the running βs=d αs/d log k of the spectral index ns of primordial sc…
Search for compensated isocurvature perturbations with Planck power spectra
Kovetz, Ely D.; Kamionkowski, Marc; Muñoz, Julian B. +2 more
In the standard inflationary scenario, primordial perturbations are adiabatic. The amplitudes of most types of isocurvature perturbations are generally constrained by current data to be small. If, however, there is a baryon-density perturbation that is compensated by a dark-matter perturbation in such a way that the total matter density is unpertu…
Information gain on reheating: The one bit milestone
Ringeval, Christophe; Martin, Jérôme; Vennin, Vincent
We show that the Planck 2015 and BICEP2/KECK measurements of the cosmic microwave background (CMB) anisotropies provide together an information gain of 0.82 ±0.13 bits on the reheating history over all slow-roll single-field models of inflation. This corresponds to a 40% improvement compared to the Planck 2013 constraints on the reheating. Our met…
Quantifying concordance in cosmology
Amara, Adam; Refregier, Alexandre; Seehars, Sebastian +1 more
Quantifying the concordance between different cosmological experiments is important for testing the validity of theoretical models and systematics in the observations. In earlier work, we thus proposed the Surprise, a concordance measure derived from the relative entropy between posterior distributions. We revisit the properties of the Surprise an…
Dark radiation and inflationary freedom after Planck 2015
Di Valentino, Eleonora; Mena, Olga; Gariazzo, Stefano +2 more
The simplest inflationary models predict a primordial power spectrum (PPS) of the curvature fluctuations that can be described by a power-law function that is nearly scale invariant. It has been shown, however, that the low-multipole spectrum of the cosmic microwave background anisotropies may hint at the presence of some features in the shape of …
Joint resonant CMB power spectrum and bispectrum estimation
Meerburg, P. Daniel; Wandelt, Benjamin; Münchmeyer, Moritz
We develop the tools necessary to assess the statistical significance of resonant features in the CMB correlation functions, combining power spectrum and bispectrum measurements. This significance is typically addressed by running a large number of simulations to derive the probability density function (PDF) of the feature-amplitude in the Gaussia…
Integrated approach to cosmology: Combining CMB, large-scale structure, and weak lensing
Amara, Adam; Refregier, Alexandre; Nicola, Andrina
Recent observational progress has led to the establishment of the standard Λ CDM model for cosmology. This development is based on different cosmological probes that are usually combined through their likelihoods at the latest stage in the analysis. We implement here an integrated scheme for cosmological probes, which are combined in a common fram…
Constraining multiplicative bias in CFHTLenS weak lensing shear data
Hill, J. Colin; Liu, Jia; Ortiz-Vazquez, Alvaro
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 background (CMB) temperature anisotropies. Similarly, a direct cross-correlation of the CFHTLenS data with Planck CMB …
Solving 3D relativistic hydrodynamical problems with weighted essentially nonoscillatory discontinuous Galerkin methods
Dietrich, Tim; Bugner, Marcus; Bernuzzi, Sebastiano +2 more
Discontinuous Galerkin (DG) methods coupled to weighted essentially nonoscillatory (WENO) algorithms allow high order convergence for smooth problems and for the simulation of discontinuities and shocks. In this work, we investigate WENO-DG algorithms in the context of numerical general relativity, in particular for general relativistic hydrodynam…