21 cm line signal from magnetic modes

The Lorentz term raises the linear matter power on small scale which leads to interesting signatures in the 21 cm signal. Numerical simulations of the resuting nonlinear density field, the distribution of ionized hydrogen and the 21 cm signal at different values of redshift are presented for magnetic fields with field strength B=5 nG, and spectral indices $n_B=-2.9, -2.2$ and -1.5 together with the adiabatic mode for the best fit data of Planck13+WP. Comparing the averaged global 21 cm signal with the projected SKA1-LOW sensitivities of the Square Kilometre Array (SKA) it might be possible to constrain the magnetic field parameters.