Abstract
The paper deals with a finite-dimensional problem of minimizing the ratio of the radius of the sphere circumscribed about a given convex body (in an arbitrary norm) to the radius of the inscribed sphere. The minimization is performed by choosing a common center of these spheres. We prove that the objective function of this problem is quasiconvex and subdifferentiable and establish a criterion for the unique solvability of the problem. The considered problem is compared with those close to it in geometric sense.
Similar content being viewed by others
References
Bonnesen, T., Fenchel, W. Theory of Convex Bodies (BCS Associates, 1987; Fazis, Moscow, 2002).
Rockafellar, R. T. Convex Analysis (Princeton University Press, 1970;Mir, Moscow, 1973).
Pshenichnyi, B. N, Convex Analysis and Extremal Problems (Nauka, Moscow, 1980) [in Russian].
Dem’yanov, V. F., Vasil’ev, L. V. Nondifferential Optimization (Nauka, Moscow, 1981) [in Russian].
Dem’yanov, V. F., Rubinov, A. M. Foundations of Nonsmooth Analysis and Quasidifferential Calculus (Nauka, Moscow, 1990) [in Russian].
Clarke, F. Optimization and Nonsmooth Analysis (John Wiley & Sons, Inc., New York, 1983; Nauka, Moscow, 1986).
Magaril-Il’yaev, G. G., Tikhomirov, V. M., Convex Analysis and Its Applications (Editorial URSS, Moscow, 2000) [in Russian].
Polovinkin, E. S., Balashov, M. V., Elements of Convex and Strongly Convex Analysis (Fizmatlit, Moscow, 2004) [in Russian].
Ivanov, G. E. Weakly Convex Sets and Functions (Fizmatlit, Moscow, 2006) [in Russian].
Makeev, V. V. “Asphericity of Shadows of a Convex Body,” J. Math. Sci., New York 140, No. 4, 535–541 (2007).
Kamenev, G. G. “The Initial Convergence Rate of Adaptive Methods for Polyhedral Approximation of Convex Bodies,” Comput. Math. Math. Phys. 48, No. 5, 724–738 (2008).
D’Ocagne, M. “Sur Certaine Figures Minimales,” Bull. Soc. Math. France 12, 168–177 (1884).
Lebesque, H. “Sur Quelques Questions de Minimum, Relatives and Courbes Orbiformes, et sur Leurs Rapports Avec le Calcul des Cariations,” J. Math. 4, No. 8, 67–96 (1921).
Vincze, St. “Über den Minimalkreisring einer Eilinie,” Acta Sci. Math. (Szeged) 11, No. 3, 133–138 (1947).
Vincze, I. “Über Kreisringe, die eine Eilinie einschlissen,” Studia Sci. Math. Hungar. 9, No. 1–2, 155–159 (1974).
Kriticos, N. “Über convexe Flachen und einschlissende Kugeln,” Math. Ann. 96, 583–586 (1927).
Barany, I. “On the Minimal Ring Containing the Boundary of Convex Body,” Acta Sci. Math. (Szeged) 52, No. 1–2, 93–100 (1988).
Zucco, A. “Minimal Shell of a Typical Convex Body,” Proc. Amer. Math. Soc. 109, 797–802 (1990).
Nikol’skii, M. S., Silin, D. B. “On the Best Approximation of Convex Compact Set by Addial Elements,” Trudy Mat. Inst. Steklov 211, 338–354 (1995).
Dudov, S. I. “Approximation of the Boundary of a Convex Compact by a Spherical Layer,” Izv. Saratovsk. Univ. 1, No. 2, 64–75 (2001).
Dudov, S. I., Zlatorunskaya, I. V. “A Uniform Estimate for a Compact Convex Set by a Ball of Arbitrary Norm,” Sb. Math. 191, No. 9–10, 1433–1458 (2000).
Dudov, S. I., Zlatorunskaya, I. V. “Best Approximation of a Compact Set by a Ball in an Arbitrary Norm,” Adv. Math. Res. 2, 81–114 (Nova Sci. Publ., Hauppauge, NY, 2003).
Dudov, S. I., Zlatorunskaya, I. V. “On an Approximate Uniform Estimate for a Compact Convex Set by a Ball of Arbitrary Norm,” Comput. Math. Math. Phys. 45, No. 3, 399–411 (2005).
Dudov, S. I. “Relations Between Several Problems of Estimating Convex Compacts by Balls,” Sb. Math. 198, No. 1, 39–53 (2007).
Dudov, S. I. “Subdifferentiability and Superdifferentiability of Distance Functions,” Comput. Math. Math. Phys. 37, No. 8, 906–912 (1997).
Dudov, S. I., Meshcheryakova, E. A. “On an Approximate Solution of the Problem of Aspherical Convex Compact Set,” Izv. Saratovsk. Univ. Ser. Matem. Mekhan. Informatika 10, No. 4, 13–17 (2010).
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © S.I. Dudov, E.A. Meshcheryakova, 2015, published in Izvestiya Vysshikh Uchebnykh Zavedenii. Matematika, 2015, No. 2, pp. 45–58.
About this article
Cite this article
Dudov, S.I., Meshcheryakova, E.A. On asphericity of convex bodies. Russ Math. 59, 36–47 (2015). https://doi.org/10.3103/S1066369X15020061
Received:
Published:
Issue Date:
DOI: https://doi.org/10.3103/S1066369X15020061