We consider the following classical autonomous variational problem: Minimize {F(u)=∫abf(u(x),u′(x)) dx : u∈AC([a,b]),u(a)=α,u(b)=β, u([a,b])⊆I}\left\{F(u)=\int_a^b f(u(x),u'(x))\,dx\,:\,u\in AC([a,b]), u(a)=\alpha, u(b)=\beta,\,u([a,b]) \subseteq I \right\} where II is a real interval, α,β∈I\alpha, \beta\in I, and f:I×R→[0,+∞)f:I\times \mathbb{R}\to [0,+\infty) is possibly neither continuous, nor coercive, nor convex; in particular f(s,⋅)f(s,\cdot) may be not convex at 00. Assuming the solvability of the relaxed problem, we prove under mild assumptions that the above variational problem has a solution, too.

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Giovanni Cupini

Dip. di Matematica, Università di Bologna, Piazza di Porta S. Donato 5, 40126 Bologna, Italy

giovanni.cupini@unibo.it
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M. Bianchini, G. Cupini. “A Relaxation Result for Non-Convex and Non-Coercive Simple Integrals.” Journal of Convex Analysis 19 (2012), No. 1, 225–248. https://doi.org/10.68381/jca19014