We prove a maximum principle for vector valued minimizers u:Ω⊂Rn→RNu: \Omega \subset\R^n\to\R^N of some functionals F(u)=∫Ωf(x,Du(x))dx.\mathcal{F}(u) = \int_{\Omega} f(x,Du(x)) dx. The main assumption on the density f(x,z)f(x,z) is a kind of "monotonicity" with respect to the N×nN \times n matrix zz. A model density is f(z)=∣z∣4−(det⁡z)2f(z)=|z|^4 - (\det z)^2, where z∈R2×2z \in \R^{2 \times 2}. We also consider relaxed functionals RF(u)=inf⁡{lim inf⁡kF(uk):uk→u}\mathcal{RF}(u) = \inf \{ \liminf\limits_{k} \mathcal{F}(u_k): \quad u_k \to u \} and we prove maximum principle under suitable assumptions.

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Francesco Leonetti

Dip. di Matematica, Università d'Aquila, 67100 L'Aquila, Italy

leonetti@univaq.it

Francesco Siepe

Dip. di Matematica, Università di Firenze, Piazza Ghiberti 27, 50122 Firenze, Italy

siepe@math.unifi.it
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F. Leonetti, F. Siepe. “Maximum Principle for Vector Valued Minimizers.” Journal of Convex Analysis 12 (2005), No. 2, 267–278. https://doi.org/10.68381/jca12019