Models relating neuron firing to oscillatory dynamics
The oscillations measured by EEG, ECoG, and MEG are thought to originate in the apical dendrites' fluctuating potentials. Try looking into the forward problem of EEG. Like the inverse problem but in reverse. Given a known source potential (apparently it's very common to model cortical neurons' LFP as a distribution of current dipoles?) you solve the Poisson equation to get the potential at the recording electrode.
I'm reading through this review right now and it's very interesting: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2234413/. 

Other avenues which seem interesting are neural mass/neural field models, especially Walter Freeman's work on neurodynamics. See: http://www.scholarpedia.org/article/Freeman_K-set.

Abstracted away from the biology a bit there's Jack Cowan's field models and stochastic neural networks. But they're both absolutely prolific and the math is dense and I'm not quite sure where to even really begin.