The general approach to solving extremal problems in various classis of analytic functions, based on duality relations between extremums, was developed. This method was developed also to the investigation extremal problems with supplementary conditions. The general theory such processes of the approximation, when the magnitude of the approximating aggregates take into account, was developed in Banach spaces. Faktorization theory for analytic functions on compact Riemann surfaces with boundary was constructed. The extremal problem analytic capacity in arbitrary domains was investigated and a theory of the extremal problems like the analytic capacity for Golubev sums was constructed. The Chebyshev theorem for the best approximation of a function of two variables by means of sum functions of one variable was proved.
Biography
Graduated from Faculty of Mathematics and Mechanics of M. V. Lomonosov Moscow State University (MSU) in 1949 (department of theory of functions). Ph.D. thesis was defended in 1953. D.Sci. thesis was defended in 1962. Professor — 1963. Honorary professor — 1996. A list of my works contains more than 180 titles.
Main publications:
Khavinson S. Ya. Extremal problems in complex analysis // AMS Translations. Series 2, v. 129, 1986, 1–114.
Khavinson S. Ya. Best Approximation by Linear Superpositions (Approximate Nomography) // AMS Translations of Mathem. Monographs. V. 159, 1997, 1–175.
S. Ya. Khavinson, “Duality relations in the theory of analytic capacity”, Algebra i Analiz, 15:1 (2003), 3–62; St. Petersburg Math. J., 15:1 (2004), 1–40
S. Ya. Havinson, “Approximations by wedge elements taking into account the values of the approximating elements”, Izv. Vyssh. Uchebn. Zaved. Mat., 2002, no. 10, 71–84; Russian Math. (Iz. VUZ), 46:10 (2002), 69–82
S. Ya. Havinson, “Extremal problems for Golubev sums”, Mat. Zametki, 65:5 (1999), 738–745; Math. Notes, 65:5 (1999), 620–626
4.
S. Ya. Havinson, “Golubev sums: a theory of extremal problems like the analytic capacity problem and of related approximation processes”, Uspekhi Mat. Nauk, 54:4(328) (1999), 75–142; Russian Math. Surveys, 54:4 (1999), 753–818
A. L. Garkavi, V. A. Medvedev, S. Ya. Havinson, “Existence of the best possible uniform approximation of a function of several variables by a sum of functions of fewer variables”, Mat. Sb., 187:5 (1996), 3–14; Sb. Math., 187:5 (1996), 623–634
A. L. Garkavi, V. A. Medvedev, S. Ya. Havinson, “On existence of a best uniform approximation of a function in two variables by the sums $\varphi(x)+\psi(y)$”, Sibirsk. Mat. Zh., 36:4 (1995), 819–827; Siberian Math. J., 36:4 (1995), 707–713
S. Ya. Havinson, “Factorization theory for single-valued analytic functions on compact Riemann surfaces with boundary”, Uspekhi Mat. Nauk, 44:4(268) (1989), 155–189; Russian Math. Surveys, 44:4 (1989), 113–156
S. Ya. Khavinson, “Factorization of single-valued analytic functions of compact bordered Riemann surfaces”, Zap. Nauchn. Sem. LOMI, 170 (1989), 285–313; J. Soviet Math., 63:2 (1993), 275–290
S. Ya. Havinson, “Representation of functions of two variables by the sums $\phi(x)+\psi(y)$”, Izv. Vyssh. Uchebn. Zaved. Mat., 1985, no. 2, 66–73; Soviet Math. (Iz. VUZ), 29:2 (1985), 81–90
S. Ya. Havinson, “On a class of sharp estimates for polynomials, moments, and analytic functions”, Uspekhi Mat. Nauk, 36:5(221) (1981), 199–200; Russian Math. Surveys, 36:5 (1981), 157–158
15.
S. Ya. Havinson, “On a class of sharp inequalities for polynomials, moments and analytic functions”, Sibirsk. Mat. Zh., 22:6 (1981), 188–207; Siberian Math. J., 22:6 (1981), 949–964
S. Ya. Khavinson, “19.5. The exact majorant problem”, Zap. Nauchn. Sem. LOMI, 81 (1978), 167–168; J. Soviet Math., 26:5 (1984), 2207
1977
17.
O. A. Muradyan, S. Ya. Khavinson, “Absolute values of the coefficients of the polynomials in Weierstrass's approximation theorem”, Mat. Zametki, 22:2 (1977), 269–276; Math. Notes, 22:2 (1977), 641–645
S. Ya. Khavinson, “On the distribution of zeroes of extremal functions in $E_p$-classes in finitely connected domains”, Mat. Zametki, 16:6 (1974), 879–885; Math. Notes, 16:6 (1974), 1122–1125
19.
S. Ya. Khavinson, “Representation of extremal functions in the classes $E_q$ in terms of Green's and Neumann's functions”, Mat. Zametki, 16:5 (1974), 707–716; Math. Notes, 16:5 (1974), 1018–1023
S. Ya. Havinson, Z. S. Romanova, “Approximation properties of finite-dimensional subspaces in $L_1$”, Mat. Sb. (N.S.), 89(131):1(9) (1972), 3–15; Math. USSR-Sb., 18:1 (1972), 1–14
S. Ya. Havinson, “Some approximation theorems involving the magnitude of the coefficients of the approximating functions”, Dokl. Akad. Nauk SSSR, 196:6 (1971), 1283–1286
S. Ya. Havinson, “A Chebyshev theorem for the approximation of a function of two variables by sums of the type $\varphi(x)+\psi(y)$”, Izv. Akad. Nauk SSSR Ser. Mat., 33:3 (1969), 650–666; Math. USSR-Izv., 3:3 (1969), 617–632
S. Ya. Khavinson, “Permissible values of coefficients of polynomials in uniform approximation of continuous functions”, Mat. Zametki, 6:5 (1969), 619–625; Math. Notes, 6:5 (1969), 834–838
S. Ya. Havinson, “Åxtremal problems for bounded analytic functions with interior side
conditions”, Uspekhi Mat. Nauk, 18:2(110) (1963), 25–98; Russian Math. Surveys, 18:2 (1963), 23–96
S. Ya. Khavinson, “The analytic capacity of sets related to the non-triviality of various classes of analytic functions, and on Schwarz's lemma in arbitrary domains”, Mat. Sb. (N.S.), 54(96):1 (1961), 3–50
S. Ya. Khavinson, “On approximation with account taken of the size of the coefficients of the approximants”, Trudy Mat. Inst. Steklov., 60 (1961), 304–324
S. Ya. Havinson, “Extremum problems for functions satisfying some supplementary restrictions inside the region and the application
of these problems to questions of approximation”, Dokl. Akad. Nauk SSSR, 135:2 (1960), 270–273
S. Ya. Havinson, “On the radius of holomorphy of functions inverse to functions which are analytic and bounded in multiply-connected regions”, Izv. Vyssh. Uchebn. Zaved. Mat., 1960, no. 5, 190–194
38.
Yu. E. Alenitsyn, S. Ya. Khavinson, “The radius of $p$-valence for bounded analytic functions in multiply-connected domains”, Mat. Sb. (N.S.), 52(94):1 (1960), 653–657
G. Ts. Tumarkin, S. Ya. Havinson, “Mutual orthogonality of boundary values of certain classes of analytic functions in multiply connected domains”, Uspekhi Mat. Nauk, 14:3(87) (1959), 173–180
G. Ts. Tumarkin, S. Ya. Khavinson, “Properties of extremum functions in extremum problems for certain classes of analytic functions with a weighed metric”, Dokl. Akad. Nauk SSSR, 119:2 (1958), 215–218
41.
G. Ts. Tumarkin, S. Ya. Havinson, “Existence in multiply-connected regions of single-valued analytic functions with a given modulus of boundary values”, Izv. Akad. Nauk SSSR Ser. Mat., 22:4 (1958), 543–562
G. Ts. Tumarkin, S. Ya. Havinson, “Analytic functions on multiply-connected regions of the class of V. I. Smirnov (class $S$)”, Izv. Akad. Nauk SSSR Ser. Mat., 22:3 (1958), 379–386
S. Ya. Havinson, “On uniqueness of functions of best approximation in the metric of the space $L_1$”, Izv. Akad. Nauk SSSR Ser. Mat., 22:2 (1958), 243–270
S. Ya. Havinson, “The radii of univalence, starlikeness and convexity of a class of analytic functions in multiply-connected domains”, Izv. Vyssh. Uchebn. Zaved. Mat., 1958, no. 3, 233–240
G. Ts. Tumarkin, S. Ya. Havinson, “An expansion theorem for analytic functions of class $E_p$ in multiply connected domains”, Uspekhi Mat. Nauk, 13:2(80) (1958), 223–228
G. Ts. Tumarkin, S. Ya. Havinson, “Classes of analytic functions in multiply connected regions represented by Cauchy–Green formulas”, Uspekhi Mat. Nauk, 13:2(80) (1958), 215–221
G. Ts. Tumarkin, S. Ya. Havinson, “On the definition of analytic functions of class $E_p$ in multiply connected domains”, Uspekhi Mat. Nauk, 13:1(79) (1958), 201–206
G. Ts. Tumarkin, S. Ya. Havinson, “Investigation of the properties of extremal functions by means of duality relations in extremal problems for classes of analytic functions in multiply connected domains”, Mat. Sb. (N.S.), 46(88):2 (1958), 195–228
G. Ts. Tumarkin, S. Ya. Havinson, “Conditions for the representability of a harmonic function by Green's formula in a multiply-connected region”, Mat. Sb. (N.S.), 44(86):2 (1958), 225–234
G. Ts. Tumarkin, S. Ya. Havinson, “On the removing of singularities for analytic functions of a certain class (class $D$)”, Uspekhi Mat. Nauk, 12:4(76) (1957), 193–199
S. Ya. Havinson, “Extremal problems for certain classes of analytic functions in finitely connected regions”, Mat. Sb. (N.S.), 36(78):3 (1955), 445–478
S. V. Konyagin, S. M. Nikol'skii, S. B. Stechkin, S. Ya. Havinson, “Aleksandr L'vovich Garkavi (on his seventieth birthday)”, Uspekhi Mat. Nauk, 50:2(302) (1995), 230–231; Russian Math. Surveys, 50:2 (1995), 461–463
L. I. Volkovyskii, A. È. Eremenko, A. A. Kondratyuk, B. Ya. Levin, S. N. Mergelyan, I. V. Ostrovskii, S. Ya. Havinson, M. N. Sheremeta, “Anatolii Asirovich Gol'dberg (on his sixtieth birthday)”, Uspekhi Mat. Nauk, 45:5(275) (1990), 201–203; Russian Math. Surveys, 45:5 (1990), 247–250