Regarding the dark matter a great Swedish professor said me recently:
As for the latter (dark matter), the issue can readily be explained by the Charge exchange process, i.e. by loosing its electric charge, ions are transferred to neutral particles - no longer affected by ambient magnetic fields. However, transferred to ions now capable of emitting electromagnetic waves. Doppler-shifted neutral particle waves being the “signum" of dark matter.
The Hydrogen atom is the heart of the Universe! Hydrogen atom - dark matter.pdf