Neutrino mass bounds from cosmology

Cosmology is at present one of the most powerful probes of neutrino properties. The advent of precision data from the cosmic microwave background and large scale structure has allowed for a very strong bound on the neutrino mass. Here, I review the status of cosmological bounds on neutrino properties with emphasis on mass bounds on light neutrinos.Comment: 6 pages, 3 figures, talk given at NOW2004 workshop, Conca Specchiulla, Italy, September 11-17, 200

CMB and Cosmological Parameters: Current Status and Prospects

The last years have been an exciting period for the field of the Cosmic Microwave Background (CMB) research. With recent CMB balloon-borne and ground-based experiments we are entering a new era of 'precision' cosmology that enables us to use the CMB anisotropy measurements to constrain the cosmological parameters and test new theoretical scenarios.Comment: 21 pages, 5 figures. Based on an invited review at the XIII Rencontres de Blois - Frontiers of the Universe, June 17-23,200

Precision of inflationary predictions and recent CMB anisotropy data

Inflationary predictions of the cosmic microwave background anisotropy are often based on the slow-roll approximation. We study the precision of these predictions and compare them with the recent data from BOOMERanG and MAXIMA-1.Comment: 4 pages, 2 figures; talk at "Cosmology and Particle Physics 2000," Verbier (Switzerland), July 17 - 28, 200

Testing the paradigm of adiabaticity

We introduce the concepts of adiabatic (curvature) and isocurvature (entropy) cosmological perturbations and present their relevance for parameter estimation from cosmic microwave background anisotropies data. We emphasize that, while present-day data are in excellent agreement with pure adiabaticity, subdominant isocurvature contributions cannot be ruled out. We discuss model independent constraints on the isocurvature contribution. Finally, we argue that the Planck satellite will be able to do precision cosmology even if the assumption of adiabaticity is relaxed.Comment: Proceedings of the 10th Marcel Grossmann Meeting, Rio de Janeiro, July 2003, 5 pages, 2 figure

The Atacama Cosmology Telescope: Cross Correlation with Planck maps

We present the temperature power spectrum of the Cosmic Microwave Background obtained by cross-correlating maps from the Atacama Cosmology Telescope (ACT) at 148 and 218 GHz with maps from the Planck satellite at 143 and 217 GHz, in two overlapping regions covering 592 square degrees. We find excellent agreement between the two datasets at both frequencies, quantified using the variance of the residuals between the ACT power spectra and the ACTxPlanck cross-spectra. We use these cross-correlations to calibrate the ACT data at 148 and 218 GHz, to 0.7% and 2% precision respectively. We find no evidence for anisotropy in the calibration parameter. We compare the Planck 353 GHz power spectrum with the measured amplitudes of dust and cosmic infrared background (CIB) of ACT data at 148 and 218 GHz. We also compare planet and point source measurements from the two experiments.Comment: 9 pages, 8 figure

From Equivalence Principles to Cosmology: Cosmic Polarization Rotation, CMB Observation, Neutrino Number Asymmetry, Lorentz Invariance and CPT

In this paper, we review the approach leading to cosmic polarization rotation observation and present the current status with an outlook. In the study of the relations among equivalence principles, we found that long-range pseudoscalar-photon interaction is allowed. Pseudoscalar-photon interaction would induce a rotation of linear polarization of electromagnetic wave propagating with cosmological/astrophysical distance. In 2002, DASI successfully observed the polarization of the cosmological microwave background radiation. In 2003, WMAP observed the correlation of polarization with temperature anisotropy at more than 10 sigma in the cosmological microwave background. From this high polarization-temperature correlation in WMAP observation, we put a limit of 0.1 rad on the rotation of linear polarization of cosmological microwave background (CMB) propagation. Pseudoscalar-photon interaction is proportional to the gradient of the pseudoscalar field. From phenomenological point of view, this gradient could be neutrino number asymmetry current, other density current, or a constant vector. In these situations, Lorentz invariance or CPT may or may not effectively be violated. In this paper, we review and compile various results. Better accuracy in CMB polarization observation is expected from PLANCK mission to be launched next year. A dedicated CMB polarization observer in the future would probe this fundamental issue more deeply.Comment: 9 pages, 2 figures, a few references with corresponding text change added in this version, invited talk given in VIII Asia-Pacific International Conference on Gravitation and Astophysics (ICGA8), August 29 - September 1, 2007, Nara Women's University, Japan, submitted to Progress of Theoretical Physics Supplemen

Cosmological Constraints from the double source plane lens SDSSJ0946+1006

We present constraints on the equation of state of dark energy, $w$, and the total matter density, $\Omega_{\mathrm{M}}$, derived from the double-source-plane strong lens SDSSJ0946+1006, the first cosmological measurement with a galaxy-scale double-source-plane lens. By modelling the primary lens with an elliptical power-law mass distribution, and including perturbative lensing by the first source, we are able to constrain the cosmological scaling factor in this system to be $\beta^{-1}=1.404 \pm 0.016$, which implies $\Omega_{\mathrm{M}}= 0.33_{-0.26}^{+0.33}$ for a flat $\Lambda$ cold dark matter ($\Lambda$CDM) cosmology. Combining with a cosmic microwave background prior from Planck, we find $w$ = $-1.17^{+0.20}_{-0.21}$ assuming a flat $w$CDM cosmology. This inference shifts the posterior by 1${\sigma}$ and improves the precision by 30 per cent with respect to Planck alone, and demonstrates the utility of combining simple, galaxy-scale multiple-source-plane lenses with other cosmological probes to improve precision and test for residual systematic biases.Comment: 9 Pages, 7 Figures. Updated version as published in MNRA