A weak lensing perspective on nonlinear structure formation with fuzzy dark matter (2211.01523v3)

Abstract: We investigate nonlinear structure formation in the fuzzy dark matter (FDM) model in comparison to cold dark matter (CDM) models from a weak lensing perspective using perturbative methods. We use Eulerian perturbation theory (PT) up to fourth order to compute the tree-level matter trispectrum and the one-loop matter spectrum and bispectrum from consistently chosen initial conditions. In addition, we predict the non-linear matter power spectra using $N$-body simulations with CDM and FDM initial conditions. We go on to derive the respective lensing spectra, bispectra and trispectra in CDM and FDM in the context of a Euclid-like weak lensing survey. Finally, we compute the attainable cumulative signal-to-noise ratios and an estimate of the attainable $\chi^2$-functionals for distinguishing FDM from CDM at particle masses $m=10^{-21}$ eV, $m = 10^{-22}$ eV and $m = 10^{-23}$ eV. We find that PT predictions cannot be used to reliably distinguish the three models in a weak lensing survey. Assuming that $N$-body simulations overestimate the late-time small-scale power in the FDM model, future weak lensing survey might be used to distinguish between the FDM and CDM cases up to a mass of $m = 10^{-23}$ eV. However, observations probing the local high-$z$ universe are probably more suited to constrain the FDM mass.