Potentials for \(\mathcal {A}\)-quasiconvexity (Q2420620)

The author of the article shows that each constant rank operator \(\mathcal {A}\) admits an exact potential \(\mathbb {B}\) in frequency space. This fact is used to prove that \(\mathcal {A}\)-quasiconvexity can be tested with compactly supported vector fields \(\omega=\mathbb {B} u\). It is also shown that \(\mathcal {A}\)-free Young measures are shifts of Young measures generated by sequences \(\mathbb {B}u_j\).