Observing primordial magnetic fields through Dark Matter

Primordial magnetic fields are often thought to be the early Universe seeds that have bloomed into what we observe today as galactic and extra-galactic fields. Owing their minuscule strength, primordial very hard detect in cosmological astrophysical observations. We show how this changes if a part of neutral Dark Matter has susceptibility. In way, by studying one can obtain information about properties fields, even latter comoving amplitude B0 ? 0.01 nG. our model is stable singlet scalar ?, which interacts with electromagnetism through Rayleigh operator ?2F??F??/?2. For present forces Z2-symmetry spontaneously broken. Later, when field redshifts below critical value, symmetry restored an "inverse phase transition". At point ? begins oscillate acts "magnetomorphic" component, inheriting space distribution. particular, for nearly flat spectrum fluctuations, carries statistically anisotropic isocurvature mode. discuss parameter consider possibility bulk composed same particles produced via freeze-in mechanism.