Constraints on non-thermal Dark Matter from Planck lensing extraction

Distortions of CMB temperature and polarization anisotropy maps caused by gravitational lensing, observable with high angular resolution and sensitivity, can be used to constrain the sterile neutrino mass, offering several advantages against the analysis based on the combination of CMB, LSS and Ly\alpha forest power spectra. As the gravitational lensing effect depends on the matter distribution, no assumption on light-to-mass bias is required. In addition, unlike the galaxy clustering and Ly\alpha forest power spectra, the projected gravitational potential power spectrum probes a larger range of angular scales, the non-linear corrections being required only at very small scales. Taking into account the changes in the time-temperature relation of the primordial plasma and the modification of the neutrino thermal potential, we compute the projected gravitational potential power spectrum and its correlation with the temperature in the presence of DM sterile neutrino. We show that the cosmological parameters are generally not biased when DM sterile neutrino is included. From this analysis we found a lower limit on DM sterile neutrino mass m_s >2.08 keV at 95% CL, consistent with the lower mass limit obtained from the combined analysis of CMB, SDSS 3D power spectrum and SDSS Ly\alpha forest power spectrum ($m_{\nu_s}>1.7$ keV). We conclude that although the information that can be obtained from lensing extraction is rather limited due to the high level of the lensing noise of Planck experiment, weak lensing of CMB offers a valuable alternative to constrain the dark matter sterile neutrino mass.Comment: 15 pages, 6 figure

Using Big Bang Nucleosynthesis to Extend CMB Probes of Neutrino Physics

We present calculations showing that upcoming Cosmic Microwave Background (CMB) experiments will have the power to improve on current constraints on neutrino masses and provide new limits on neutrino degeneracy parameters. The latter could surpass those derived from Big Bang Nucleosynthesis (BBN) and the observationally-inferred primordial helium abundance. These conclusions derive from our Monte Carlo Markov Chain (MCMC) simulations which incorporate a full BBN nuclear reaction network. This provides a self-consistent treatment of the helium abundance, the baryon number, the three individual neutrino degeneracy parameters and other cosmological parameters. Our analysis focuses on the effects of gravitational lensing on CMB constraints on neutrino rest mass and degeneracy parameter. We find for the PLANCK experiment that total (summed) neutrino mass $M_{\nu} > 0.29$ eV could be ruled out at $2\sigma$ or better. Likewise neutrino degeneracy parameters $\xi_{\nu_{e}} > 0.11$ and $| \xi_{\nu_{\mu/\tau}} | > 0.49$ could be detected or ruled out at $2\sigma$ confidence, or better. For POLARBEAR we find that the corresponding detectable values are $M_\nu > 0.75 {\rm eV}$, $\xi_{\nu_{e}} > 0.62$, and $| \xi_{\nu_{\mu/\tau}}| > 1.1$, while for EPIC we obtain $M_\nu > 0.20 {\rm eV}$, $\xi_{\nu_{e}} > 0.045$, and $|\xi_{\nu_{\mu/\tau}}| > 0.29$. Our forcast for EPIC demonstrates that CMB observations have the potential to set constraints on neutrino degeneracy parameters which are better than BBN-derived limits and an order of magnitude better than current WMAP-derived limits.Comment: 27 pages, 11 figures, matches published version in JCA

Neutrino physics from precision cosmology

Cosmology provides an excellent laboratory for testing various aspects of neutrino physics. Here, I review the current status of cosmological searches for neutrino mass, as well as other properties of neutrinos. Future cosmological probes of neutrino properties are also discussed in detail.Comment: 30 pages, 10 figures, Review article for Progress in Particle and Nuclear Physics, references update

SU(2)CMB_{\rm CMB} and the cosmological model: angular power spectra

Driven by the CMB temperature-redshift ($T$-$z$) relation as demanded by deconfining SU(2) Yang-Mills thermodynamics, an according cosmological model is proposed and analysed. This model -- SU(2)_\CMB -- exhibits a dark sector, representing $\Lambda$CDM with a certain late-time dark-matter density which transitions to a reduced (present-day) density parameter at high $z$. We statistically analyse constraints on cosmological parameters directly imposed by the values of the standard co-moving ruler $r_d$ and the angular size of the sound horizon $\theta_*$. Compared to the $\Lambda$CDM best fit to 2015 Planck data, we require an increased (present-day) dark matter density when $r_d\cdot H_0=$\,const and a value $H_0\sim 73.5$ km\,s$^{-1}$Mpc$^{-1}$ -- typical for local extractions -- are used. The ratio between the density parameters of primordial and late-time dark matter ranges between 0.5 and 0.7. We confirm this trend by fitting the predictions of SU(2)_\CMB, obtained from a modified CLASS code, to the angular power spectra TT, TE, and EE. We consider adiabatic, scalar primordial curvature perturbations and distinguish two treatments of thermal quasi-particles in the perturbation equations. Best fits predict a red-tilted primordial power spectrum. Moreover, a low baryon density is obtained compared with the coincidence value of BBN, the $\Lambda$CDM best fit of the 2015 Planck data, and the observed deuterium abundance. Our derived values of $H_0$ support the results of local cosmological observations. Also, there is a tendency for late reionisation.Comment: 16 pp, 12 fig

Constraining Fundamental Physics with Future CMB Experiments

The Planck experiment will soon provide a very accurate measurement of Cosmic Microwave Background anisotropies. This will let cosmologists determine most of the cosmological parameters with unprecedented accuracy. Future experiments will improve and complement the Planck data with better angular resolution and better polarization sensitivity. This unexplored region of the CMB power spectrum contains information on many parameters of interest, including neutrino mass, the number of relativistic particles at recombination, the primordial Helium abundance and the injection of additional ionizing photons by dark matter self-annihilation. We review the imprint of each parameter on the CMB and forecast the constraints achievable by future experiments by performing a Monte Carlo analysis on synthetic realizations of simulated data. We find that next generation satellite missions such as CMBPol could provide valuable constraints with a precision close to that expected in current and near future laboratory experiments. Finally, we discuss the implications of this intersection between cosmology and fundamental physics.Comment: 11 pages, 14 figure

Scaling relations for galaxy clusters: properties and evolution

Well-calibrated scaling relations between the observable properties and the total masses of clusters of galaxies are important for understanding the physical processes that give rise to these relations. They are also a critical ingredient for studies that aim to constrain cosmological parameters using galaxy clusters. For this reason much effort has been spent during the last decade to better understand and interpret relations of the properties of the intra-cluster medium. Improved X-ray data have expanded the mass range down to galaxy groups, whereas SZ surveys have openened a new observational window on the intracluster medium. In addition,continued progress in the performance of cosmological simulations has allowed a better understanding of the physical processes and selection effects affecting the observed scaling relations. Here we review the recent literature on various scaling relations, focussing on the latest observational measurements and the progress in our understanding of the deviations from self similarity.Comment: 38 pages. Review paper. Accepted for publication in Space Science Reviews (eds: S. Ettori, M. Meneghetti). This is a product of the work done by an international team at the International Space Science Institute (ISSI) in Bern on "Astrophysics and Cosmology with Galaxy Clusters: the X-ray and Lensing View

CMBPol Mission Concept Study: Gravitational Lensing

Gravitational lensing of the cosmic microwave background by large-scale structure in the late universe is both a source of cosmological information and a potential contaminant of primordial gravity waves. Because lensing imprints growth of structure in the late universe on the CMB, measurements of CMB lensing will constrain parameters to which the CMB would not otherwise be sensitive, such as neutrino mass. If the instrumental noise is sufficiently small (<~ 5 uK-arcmin), the gravitational lensing contribution to the large-scale B-mode will be the limiting source of contamination when constraining a stochastic background of gravity waves in the early universe, one of the most exciting prospects for future CMB polarization experiments. High-sensitivity measurements of small-scale B-modes can reduce this contamination through a lens reconstruction technique that separates the lensing and primordial contributions to the B-mode on large scales. A fundamental design decision for a future CMB polarization experiment such as CMBpol is whether to have coarse angular resolution so that only the large-scale B-mode (and the large-scale E-mode from reionization) is measured, or high resolution to additionally measure CMB lensing. The purpose of this white paper is to evaluate the science case for CMB lensing in polarization: constraints on cosmological parameters, increased sensitivity to the gravity wave B-mode via lens reconstruction, expected level of contamination from non-CMB foregrounds, and required control of beam systematics

Massive neutrinos and cosmology

The present experimental results on neutrino flavour oscillations provide evidence for non-zero neutrino masses, but give no hint on their absolute mass scale, which is the target of beta decay and neutrinoless double-beta decay experiments. Crucial complementary information on neutrino masses can be obtained from the analysis of data on cosmological observables, such as the anisotropies of the cosmic microwave background or the distribution of large-scale structure. In this review we describe in detail how free-streaming massive neutrinos affect the evolution of cosmological perturbations. We summarize the current bounds on the sum of neutrino masses that can be derived from various combinations of cosmological data, including the most recent analysis by the WMAP team. We also discuss how future cosmological experiments are expected to be sensitive to neutrino masses well into the sub-eV range.Comment: 122 pages, 23 figures, misprints corrected and references added. Review article to be published in Physics Report