Euclid: Modelling massive neutrinos in cosmology -- a code comparison

Understand

The measurement of the absolute neutrino mass scale from cosmological large-scale clustering data is one of the key science goals of the Euclid mission.

• Such a measurement relies on precise modelling of the impact of neutrinos on structure formation, which can be studied with $N$-body simulations.
• Here we present the results from a major code comparison effort to establish the maturity and reliability of numerical methods for treating massive neutrinos.
• The comparison includes eleven full $N$-body implementations (not all of them independent), two $N$-body schemes with approximate time integration, and four additional codes that directly predict or emulate the matter power spectrum.