Search Publications
Weak-lensing mass calibration of the Atacama Cosmology Telescope equatorial Sunyaev-Zeldovich cluster sample with the Canada-France-Hawaii telescope stripe 82 survey
Bond, J. R.; Calabrese, E.; Huffenberger, K. M. +39 more
Mass calibration uncertainty is the largest systematic effect for using clusters of galaxies to constrain cosmological parameters. We present weak lensing mass measurements from the Canada-France-Hawaii Telescope Stripe 82 Survey for galaxy clusters selected through their high signal-to-noise thermal Sunyaev-Zeldovich (tSZ) signal measured with th…
Primordial features and Planck polarization
Starobinsky, Alexei A.; Hazra, Dhiraj Kumar; Smoot, George F. +1 more
With the Planck 2015 Cosmic Microwave Background (CMB) temperature and polarization data, we search for possible features in the primordial power spectrum (PPS). We revisit the Wiggly Whipped Inflation (WWI) framework and demonstrate how generation of some particular primordial features can improve the fit to Planck data. WWI potential allows the …
Another look at distortions of the Cosmic Microwave Background spectrum
Negrello, M.; Lapi, A.; De Zotti, G. +2 more
We review aspects of Cosmic Microwave Background (CMB) spectral distortions which do not appear to have been fully explored in the literature. In particular, implications of recent evidences of heating of the intergalactic medium (IGM) by feedback from active galactic nuclei are investigated. Taking also into account the IGM heating associated to …
Differential cosmic expansion and the Hubble flow anisotropy
Wiltshire, David L.; Bolejko, Krzysztof; Nazer, M. Ahsan
The Universe on scales 01-100 h-1Mpc is dominated by a cosmic web of voids, filaments, sheets and knots of galaxy clusters. These structures participate differently in the global expansion of the Universe: from non-expanding clusters to the above average expansion rate of voids. In this paper we characterize Hubble expansion anisotropie…
Testing chirality of primordial gravitational waves with Planck and future CMB data: no hope from angular power spectra
Melchiorri, Alessandro; Shiraishi, Maresuke; Gerbino, Martina +2 more
We use the 2015 Planck likelihood in combination with the Bicep2/Keck likelihood (BKP and BK14) to constrain the chirality, χ, of primordial gravitational waves in a scale-invariant scenario. In this framework, the parameter χ enters theory always coupled to the tensor-to-scalar ratio, r, e.g. in combination of the form χ ṡ r. Thus, the capability…
Iron Kα line of boson stars
Cao, Zheng; Bambi, Cosimo; Zhou, Menglei +3 more
The present paper is a sequel to our previous work [1] in which we studied the iron Kα line expected in the reflection spectrum of Kerr black holes with scalar hair. These metrics are solutions of Einstein's gravity minimally coupled to a massive, complex scalar field. They form a continuous bridge between a subset of Kerr black holes and a family…
Cosmological constraint on the light gravitino mass from CMB lensing and cosmic shear
Osato, Ken; Yoshida, Naoki; Kamada, Ayuki +2 more
Light gravitinos of mass lesssim O (10) eV are of particular interest in cosmology, offering various baryogenesis scenarios without suffering from the cosmological gravitino problem. The gravitino may contribute considerably to the total matter content of the Universe and affect structure formation from early to present epochs. After the gravitino…
Inflation in the closed FLRW model and the CMB
Bonga, Béatrice; Gupt, Brajesh; Yokomizo, Nelson
Recent cosmic microwave background (CMB) observations put strong constraints on the spatial curvature via estimation of the parameter Ωk assuming an almost scale invariant primordial power spectrum. We study the evolution of the background geometry and gauge-invariant scalar perturbations in an inflationary closed FLRW model and calcula…
Cosmic microwave background and inflation in multi-fractional spacetimes
Calcagni, Gianluca; Kuroyanagi, Sachiko; Tsujikawa, Shinji
We use FIRAS and PLANCK 2015 data to place observational bounds on inflationary scenarios in multi-fractional spacetimes with q-derivatives. While a power-law expansion in the geometric time coordinate is subject to the usual constraints from the tensor-to-scalar ratio, model-independent best fits of the black-body and scalar spectra yield upper l…
Information gains from cosmological probes
Amara, A.; Refregier, A.; Grandis, S. +2 more
In light of the growing number of cosmological observations, it is important to develop versatile tools to quantify the constraining power and consistency of cosmological probes. Originally motivated from information theory, we use the relative entropy to compute the information gained by Bayesian updates in units of bits. This measure quantifies …