Theoretical estimates of two-point shear correlation functions using tangled magnetic fields

Abstract

The existence of primordial magnetic fields can induce matter perturbations with additional power at small scales as compared to the usual ΛCDM model.We study its implication within the context of a two-point shear correlation function from gravitational lensing. We show that a primordial magnetic field can leave its imprints on the shear correlation function at angular scales a few arcminutes. The results are compared with CFHTLS data, which yield some of the strongest known constraints on the parameters (strength and spectral index) of the primordial magnetic field. We also discuss the possibility of detecting sub-nano Gauss fields using future missions such as SNAP.