High frequency radio emission may originate from scales as small as the
innermost accretion disk, and can thus probe directly the relativistic electrons
and the magnetic fields in the coronal gas of radio quiet AGN.
I will present simulations of the time evolution of the distribution functions of
relativistic electrons following their injection due to a coronal reconnection event.
The electrons cool through Compton scattering, producing a pulse of X-ray
emission, and through synchrotron emission, producing a pulse of high frequency
radio emission. Future simultaneous monitoring of X-ray and mm emission may allow
to probe directly the coronal heating and cooling mechanisms.
I wil also briefly point out the false detections of correlated variability when two
red light curves are correlated, as we found in a recent study of simultaneous radio
and X-ray observation of three AGN. I will also describe how these biases can be
minimised in future studies.