Radiation in classical and quantum mechanics

[hokhani]

In classical electrodynamics, acceleration of charge generates radiation. In quantum mechanics, radiation is generated by transition of charge from higher quantum lever to lower. Is any relationship between the inter-level transition and acceleration?
Also, how about the radiation of a charge accelerated in a uniform electric field, which there are not stationary states. How to obtain frequency of the radiated light?

 

[Dale]

Is any relationship between the inter-level transition and acceleration?

Both cases have a time-varying dipole moment.

 

[tech99]

I suppose in a simple way that if we accelerate a charge using an alternating electric field, the radiated energy will, as always, be in quanta and the energy of each of these quanta will depend on the frequency of the alternating field.