Far Eastern Mathematical Journal

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On the uniqueness theorems for the transformations of sets and condensers in the plane


V. N. Dubinin, E. G. Prilepkina

2002, issue 2, P. 137–149


Abstract
The contraction transformation of the compact sets and the separating transformation of the sets and the condensers in the extended complex plane are considered. The first transformation is well-known in the theory of functions and in the potential theory. The second transformation was introduced by the first-named author and it has many applications in the geometric theory of functions of a complex variable. In the present paper, the necessary and sufficient condition for the conservation of the logarithmic capacity under the contraction transformation is proved. Also, we give the such conditions for the separating transformation of the condensers and domains. As the applications, the uniqueness of the extremal compact set and the extremal configuration in the some known problems of the potential theory is obtained. Our results supplement the uniqueness theorems for the symmetrization transformations which were proved by J. A. Jenkins, I. P. Mityuk, V. A. Shlyk and other mathematicians.

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References

[1] V. N. Dubinin, Capacities and geometric transformations of subsets in n-space, Geometric and Functional Analysis, 3:4 (1993), 342–369.
[2] A. II Baernstein, A unified approach to symmetrization, Partial differential equations of elliptic type, Proceedings of the conference (Cortona, 1992), Cambridge Univ. Press, 1994, 77–91.
[3] V. N. Dubinin, Simmetrizaciya v geometricheskoj teorii funkcij kompleksnogo peremennogo, Uspexi matematicheskix nauk, 49:1 (1994), 3–76.
[4] J. A. Jenkins, Some uniqueness rezults in the theory of symmetrization, Ann. math., 75:2 (1962), 223–230.
[5] V. K. Xejman, Mnogolistnye funkcii, In. lit., M., 1960.
[6] M. Ohtsuka, Dirichlet problem, extremal length and prime ends, New-York, 1970.
[7] I. P. Mityuk, Simmetrizacionnye metody i ix primenenie v geometricheskoj teorii funkcij, Vvedenie v simmetrizacionnye metody, Kubanskij gosuniversitet, Krasnodar, 1980.
[8] V. A. Shlyk, O teoreme edinstvennosti dlya simmetrizacii proizvol'nyx kondensatorov, Sib. matem. zhurnal, 1982, № 2, 165–175.
[9] I. P. Mityuk, Teorema edinosti pri simmetrizacii $S^{(1)}_?$, Dop. AN URSR, 1970, № 9, 778–779.
[10] I. P. Mityuk, V. A. Shlyk, O spiral'no-usrednyayushhej simmetrizacii i nekotoryx ee primeneniyax, Izv. Severo-Kavkazskogo nauch. centra vyssh. shkoly, 1973, № 4, 61–64.
[11] I. P. Mityuk, Teoremy edinstvennosti pri simmetrizacii oblastej i kondensatorov, Nekotor. vopr. sovrem. teorii funkcij, Novosibirsk, 1976, 101–108.
[12] A. Baernstein, Integral means, univalent functions and circular symmetrization, Acta Math., 133:3-4 (1974), 139–169.
[13] A. Yu. Solynin, Polyarizaciya i funkcional'nye neravenstva, Algebra i analiz, 8:6 (1996), 148–185.
[14] N. S. Landkof, Osnovy sovremennoj teorii potenciala, Nauka, M., 1966.
[15] T. Ransford, Potential theory in the complex plane, Cambridge Univ. Press., 1995.
[16] E. G. Axmedzyanova, Teorema edinstvennosti dlya radial'nogo preobrazovaniya zamknutyx mnozhestv, Preprint № 4 IPM DVO RAN., 1998.
[17] L. V. Kovalev, Monotonnost' obobshhennogo privedennogo modulya, Zap.nauchn. semin. POMI, 276, 2001, 219–236.
[18] E. G. Axmedzyanova, V. N. Dubinin, Radial'nye preobrazovaniya mnozhestv i neravenstva dlya transfinitnogo diametra, Izvestiya vuzov. Matematika, 1999, № 4, 3–8.

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