Bergische Universität Wuppertal

Fachbereich Mathematik

Margareta Heilmann

heilmann@math.uni-wuppertal.de

Prof. Dr. Margareta Heilmann
       Bergische Universität Wuppertal
       Fachbereich Mathematik
       D-42097 Wuppertal

Telefon: +49 202 439 2759

Büro: Gaußstr.  20
            Raum D 13.02

          Veröffentlichungen

M. Heilmann, M. Wagner:
Strong converse results for Bernstein-Durrmeyer operators and their quasi-interpolants.
Submitted.

H. Gonska, M. Heilmann, I. Rasa:
Differentiated Bernstein polynomials revisited.
Submitted.

H. Gonska, M. Heilmann, I. Rasa:
Convergence of iterates of genuine and ultraspherical Durrmeyer operators to the limiting semigroup: C²-estimates.
Journal Approx. Theory, 160, 243-255 (2009).

U. Abel, M. Heilmann:
The complete asymptotic expansion for Bernstein-Durrmeyer operators with Jacobi weights.
Mediterranean Journal of Mathematics, 487-499 (2004).

M. Heilmann:
Rodriguez-type representation for the eigenfunctions of Durrmeyer-type operators.
       Result. Math.,44, 97-105 (2003).

M. Heilmann:
Eigenfunctions od Durrmeyer-type modifications of Meyer-König and Zeller operators.
      Journal Approx. Theory, 125/1, 63-73 (2003).

M. Heilmann:
Commutativity of Durrmeyer-type modifications of Meyer-König and Zeller and Baskakov-operators.
      B. Bojanov (ed.) et al., Constructive Theory of Functions, Proceedings of the international conference, Varna, Bulgaria, June 19-23, 2002. Sofia: DARBA. 295-301 (2003).

M. Heilmann:
Saturation of linear combinations of Baskakov-Durrmeyer-type operators
      Appl. Anal., 59, No. 1-4, 93-107 (1995).

M. Heilmann:
Explicit Voronovskaja-type results for linear combinations of BDT-operators.
      Approximation Theory Appl., 11, No. 1, 54-61 (1995).

M. Heilmann:
Rate of approximation of weighted derivatives by linear combinations of SMD-operators.
     D. Braess (ed.) et al.,Numerical methods in approximation theory. Vol. 9: Proceedings of the conference held in Oberwolfach, Germany, November 24-30, 1991. Basel: Birkhäuser. ISNM, Int. Ser. Numer. Math. 105, 97-115 (1992).

M. Heilmann, M. W. Müller:
Equivalence of a weighted modulus of smoothness and a modified weighted K-functional,
      P. Nevai, A. Pinkus (eds.), Progress in approximation theory, Academic Press, Boston, MA, 467-473 (1991).

M. Heilmann, M. W. Müller:
Direct and converse results on simultaneous approximation by the method of Bernstein-Durrmeyer operators.
      Algorithms for approximation II, Proc. 2nd Int. Conf., Shrivenham/UK 1988, 107-116 (1990).

M. Heilmann, M. W. Müller:
Weighted simultaneous L_p-approximation by the method of Baskakov-Durrmeyer operators.
       Approximation Theory VI, Proc. 6th Int. Symp., College Station/TX (USA) 1989, Vol. 1, 331-332 (1989).

M. Heilmann, M. W. Müller:
Direct and converse results on weighted simultaneous approximation by the method of operators of Baskakov-Durrmeyer type.
        Result. Math. 16 No.3/4, 228-242 (1989).

M. Heilmann:
On simultaneous approximation by optimal algebraic polynomials.
        Result. Math. 16, No.1/2, 77-81 (1989).

M. Heilmann:
Direct and converse results for operators of Baskakov-Durrmeyer type.
        Approximation Theory Appl. 5, No.1, 105-127 (1989).

M. Heilmann, M. W. Müller:
On simultaneous approximation by the method of Baskakov-Durrmeyer operators.
        Numer. Funct. Anal. Optimization 10, No.1/2, 127-138 (1989).

M. Heilmann:
Commutativity of operators from Baskakov-Durrmeyer type.
        Constructive theory of functions, Proc. Int. Conf., Varna/Bulg. 1987, 197-206 (1988).

M. Heilmann:
        L_p-saturation of some modified Bernstein operators.
J. Approximation Theory 54, No.3, 160-273 (1988).