CFHTLS weak-lensing constraints on the neutrino masses^*

¹ Argelander-Institut für Astronomie, Auf dem Hügel 71, 53121 Bonn, Germany e-mail: tereno@astro.uni-bonn.de
² Institut d'Astrophysique de Paris, CNRS UMR 7095 & UPMC, 98 bis bd Arago, 75014 Paris, France
³ Laboratoire d'Astrophysique de Marseille, 38 rue Joliot-Curie, 13388 Marseille, France
⁴ Université de Provence – Aix - Marseille I , Marseille, France
⁵ INAF – Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy
⁶ Shanghai Key Lab for Astrophysics, Shanghai Normal University, 200234 Shanghai, PR China

Received: 3 October 2008
Accepted: 7 February 2009

Abstract

Context. Oscillation experiments yield strong evidence that at least some neutrinos are massive. As a hot dark-matter component, massive neutrinos should modify the expansion history of the Universe as well as the evolution of cosmological perturbations, in a different way from cold dark matter or dark energy.

Aims. We use the latest release of CFHTLS cosmic-shear data to constrain the sum of the masses of neutrinos, assuming three degenerate mass states. We also consider a joint analysis including other cosmological observables, notably CMB anisotropies, baryonic acoustic oscillations, and distance modulus from type Ia supernovae.

Methods. Combining CAMB with a lensing code, we compute the aperture mass variance using a suitable recipe to deal with matter perturbations in the non-linear regime. The statistical analysis is performed by sampling an 8-dimensional likelihood on a regular grid as well as using the importance sampling technique.

Results. We obtain the first constraint on neutrino masses based on cosmic-shear data, and combine CFHTLS with WMAP, SDSS, 2dFGRS, Gold-set, and SNLS data. The joint analysis yields 0.03 eV  eV at the 95% confidence level. The preference for massive neutrinos vanishes when systematics are included.