DEMNUni: ISW, Rees-Sciama, and weak-lensing in the presence of massive neutrinos

In the July 2016 issue of JCAP, for the first time in the literature, Darklight fellow Dr. Carmelita Carbone and co-authors present a full reconstruction of the total (linear and non-linear) ISW/Rees-Sciama effect in the presence of massive neutrinos, together with its cross-correlations with CMB-lensing and weak-lensing signals. The present analyses make use of all-sky maps extracted via ray-tracing across the gravitational potential distribution provided by the "Dark Energy and Massive Neutrino Universe" (DEMNUni) project, a set of large-volume, high-resolution cosmological N-body simulations, where neutrinos are treated as separate collisionless particles. They correctly recover, at 1−2% accuracy, the linear predictions from CAMB. Concerning the CMB-lensing and weak-lensing signals, they also recover, with similar accuracy, the signal predicted by Boltzmann codes, once non-linear neutrino corrections to Halofit are accounted for. Interestingly, in the ISW/Rees-Sciama signal, and its cross correlation with lensing, they find an excess of power with respect to the massless case, due to free streaming neutrinos, roughly at the transition scale between the linear and non-linear regimes. The excess is ∼5−10% at l∼100 for the ISW/Rees-Sciama auto power spectrum, depending on the total neutrino mass Mν, and becomes a factor of ∼4 for Mν=0.3 eV, at l∼600, for the ISW/Rees-Sciama cross power with CMB-lensing. This effect should be taken into account for the correct estimation of the CMB temperature bispectrum in the presence of massive neutrinos.

ISWandLening_Maps

Top panel: projected mono-dipole-subtracted full-sky maps of the ISW-RS signal for Mν = 0 eV (left) and Mν = 0.17 eV (right). They do not include primary CMB anisotropies. Bottom panel: projected mono-dipole-subtracted full-sky maps of the lensing potential for Mν = 0 eV (left) and Mν = 0.53 eV (right); bars indicate the modulus and orientation of the deflection-angle field α.

To read the full paper:

Carbone, C., Petkova, M., Dolag, K., DEMNUni: ISW, Rees-Sciama, and weak-lensing in the presence of massive neutrinos, JCAP, Issue 07, art. id 034, 07/2016;

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