We look for the minimizers of the functional Jλ(Ω)=λ∣Ω∣−P(Ω)\mathrm{J}_\lambda(\Omega) = \lambda|\Omega| - P(\Omega) among planar convex domains constrained to lie into a given ring. We prove that, according to the values of the parameter λ, the solutions are either a disc or a polygon. In this last case, we describe completely the polygonal solutions by reducing the problem to a finite dimensional optimization problem. We recover classical inequalities for convex sets involving area, perimeter and inradius or circumradius and find a new one.

Contact details are reproduced from the original publication and may be historical.

Chiara Bianchini

Institut Elie Cartan, Université Henri Poincaré, Blvd des Aiguillettes, B.P. 70239, 54506 Vandoeuvre-les-Nancy, France

chiara.bianchini@iecn.u-nancy.fr

Antoine Henrot

Institut Elie Cartan, Université Henri Poincaré, Blvd des Aiguillettes, B.P. 70239, 54506 Vandoeuvre-les-Nancy, France

antoine.henrot@iecn.u-nancy.fr
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C. Bianchini, A. Henrot. “Optimal Sets for a Class of Minimization Problems with Convex Constraints.” Journal of Convex Analysis 19 (2012), No. 3, 725–758. https://doi.org/10.68381/jca19039