Maimeskul V. V.
Ukr. Mat. Zh. - 1996. - 48, № 6. - pp. 852-856
For a function ω, we establish a condition sufficient for the sum ∑i, ω(diam φ(L i )) to be finite for any quasiconformal curve L i , simply connected domain Ω, and a function φ which conformally and univalently maps this domain onto the unit disk. Here, L i denote the components of Ω∩L.
Ukr. Mat. Zh. - 1993. - 45, № 11. - pp. 1522–1533
Upper and lower bounds are established for the rate of rational approximation of functions piecewise analytic on tangent continua. In some special cases, these bounds are coordinated depending on the mutual location of the continua.
Ukr. Mat. Zh. - 1993. - 45, № 7. - pp. 982–991
Quasianalytic classes of functions in a Jordan domainG are defined. We consider classes of functions defined by conditions imposed on the decrease rate of the best uniform polynomial approximations and investigate the dependence of the quasianalyticity of these classes on the geometric structure of a domain.
Ukr. Mat. Zh. - 1990. - 42, № 6. - pp. 772–777
Ukr. Mat. Zh. - 1988. - 40, № 5. - pp. 647-649