ON ARTIN'S BRAID GROUP AND POLYCONVEXITY IN THE CALCULUS OF VARIATIONS
ON ARTIN'S BRAID GROUP AND POLYCONVEXITY IN THE CALCULUS OF VARIATIONS
Let Ω ⊂ R 2 be a bounded Lipschitz domain and let+ -→ R be a Carathèodory integrand such that F (x, •) is polyconvex for L 2 -a.e.x ∈ Ω. Moreover assume that F is bounded from below and satisfies the condition F (x, ξ)∞ as det ξ 0 …