Characterizations of elements of best approximation in non-Archimedean normed spaces
Chebychev Sets which are not Suns.
Chebyshev Approximation by Spline Functions with Free Knots.
Chebyshev Centres in Normed Spaces
Chebyshev coficients for L1-preduals and for spaces with the extension property.
We apply the Chebyshev coefficients λf and λb, recently introduced by the authors, to obtain some results related to certain geometric properties of Banach spaces. We prove that a real normed space E is an L1-predual if and only if λf(E) = 1/2, and that if a (real or complex) normed space E is a P1 space, then λb(E) equals λb(K), where K is the ground field of E.
Chebyshev optimal starting approximation by families with the weak betweenness property
Chebyshev polynomials and some methods of approximation.
Chebyshev type estimates in prime number theory.
Chebyshevian splines [Book]
Common fixed point results and its applications to best approximation in ordered semi-convex structure.
Common fixed points versus invariant approximation in nonconvex sets.
Comparisons Between Best Polynomial Approximations and Interpolating Polynomials.
Concertina-Loke Movements of the Error Curve in the Alternation Theorem.
Containing l1 or c0 and best approximation.
The purpose of this paper is to obtain sufficient conditions, for a Banach space X to contain or exclude c0 or l1, in terms of the sets of best approximants in X for the elements in the bidual space.
Continuous dependence of the local strong unicity constant on domain.
Correction to the paper: Continuous dependence of the local strong unicity constant on domain (Aequationes Math. 46 (1993), 229-242).
Correction to “Walsh equiconvergence for best approximates” Studia Math.. 77 (1984), 523-528
Corrigendum to "The Existence and Unicity of Best Approximations".
Degree of Best Approximation by Trigonometric Blending Functions.
Der Satz von Fenchel in der konvexen Optimierung.