Partial regularity for minima of higher-order quasiconvex integrands with natural Orlicz growth
Christopher Irving
TL;DR
The paper studies partial regularity for minimisers of higher-order quasiconvex functionals with natural growth governed by an $N$-function $\varphi$ under the $\Delta_2$ and $\nabla_2$ conditions. It develops an $\varepsilon$-regularity framework by combining a Caccioppoli inequality of the second kind with a harmonic-approximation argument based on a Lipschitz truncation, yielding an excess-decay mechanism that implies $C^{k,\alpha}$ regularity away from a singular set. The results extend known $k=1$ quasiconvex regularity to higher order without requiring quantitative second-derivative bounds on the integrand and, in addition, cover strong local minimisers. This work advances the understanding of regularity under general Orlicz-type growth and higher-order quasiconvexity, with potential implications for vector-valued variational problems in the Orlicz setting.
Abstract
A partial regularity theorem is presented for minimisers of $k$th-order functionals subject to a quasiconvexity and general growth condition. We will assume a natural growth condition governed by an $N$-function satisfying the $Δ_2$ and $\nabla_2$ conditions, assuming no quantitative estimates on the second derivative of the integrand; this is new even in the $k = 1$ case. These results will also be extended to the case of strong local minimisers.
