Oscillation and Concentration in Sequences of PDE Constrained Measures

We show that for constant rank partial differential operators A whose wave cones are spanning, generalized Young measures generated by bounded sequences of A-freemeasures can be characterized by duality with A-quasiconvex integrands of linear growth. This includes a characterization of the concentration effects in such sequences that allows us to conclude that, in sharp contrast to the oscillation effects, the concentration always has A-free structure.