ArticleOriginal scientific text

Title

Degenerate evolution problems and Beta-type operators

Authors 1, 2

Affiliations

  1. Department of Economic Sciences, University of Bari, Via C. Rosalba, 53 70124 Bari, Italy
  2. Department of Mathematics, Polytechnic of Bari, Via E. Orabona, 4 70125 Bari, Italy

Abstract

The present paper is concerned with the study of the differential operator Au(x):=α(x)u''(x)+β(x)u'(x) in the space C([0,1)] and of its adjoint Bv(x):=((αv)'(x)-β(x)v(x))' in the space L1(0,1), where α(x):=x(1-x)/2 (0≤x≤1). A careful analysis of their main properties is carried out in view of some generation results available in [6, 12, 20] and [25]. In addition, we introduce and study two different kinds of Beta-type operators as a generalization of similar operators defined in [18]. Among the corresponding approximation results, we show how they can be used in order to represent explicitly the solutions of the Cauchy problems associated with the operators A and Ã, where à is equal to B up to a suitable bounded additive perturbation.

Keywords

approximation process, C0-semigroups of contractions, Beta-type operators, differential operators

Bibliography

  1. F. Altomare, Limit semigroups of Bernstein-Schnabl operators associated with positive projections, Ann. Scuola Norm. Sup. Pisa Cl. Sci. (4) 16 (1989), 259-279.
  2. F. Altomare and A. Attalienti, Forward diffusion equations and positive operators, Math. Z. 225 (1997), 211-229.
  3. F. Altomare and M. Campiti, Korovkin-type Approximation Theory and its Applications, de Gruyter Stud. in Math. 17, de Gruyter, Berlin, 1994.
  4. F. Altomare and I. Carbone, On some degenerate differential operators on weighted function spaces, J. Math. Anal. Appl. 213 (1997), 308-333.
  5. A. Attalienti, Generalized Bernstein-Durrmeyer operators and the associated limit semigroup, J. Approx. Theory 99 (1999), 289-309.
  6. A. Attalienti and M. Campiti, On the generation of C0-semigroups in L1(I), preprint, Bari University, 1998.
  7. M. Campiti and G. Metafune, Approximation properties of recursively defined Bernstein-type operators, J. Approx. Theory 87 (1996), 243-269.
  8. M. Campiti and G. Metafune, Evolution equations associated with recursively defined Bernstein-type operators, ibid., 270-290.
  9. M. Campiti and G. Metafune, Approximation of solutions of some degenerate parabolic problems, Numer. Funct. Anal. Optim. 17 (1996), 23-35.
  10. M. Campiti and G. Metafune, Ventcel's boundary conditions and analytic semigroups, Arch. Math. (Basel) 70 (1998), 377-390.
  11. M. Campiti, G. Metafune and D. Pallara, Degenerate self-adjoint evolution equations on the unit interval, Semigroup Forum 57 (1995), 1-36.
  12. P. Clément and C. A. Timmermans, On C0-semigroups generated by differential operators satisfying Ventcel's boundary conditions, Indag. Math. 89 (1986), 379-387.
  13. N. S. Ethier and T. G. Kurtz, Markov Processes, Characterization and Convergence, Wiley, 1986.
  14. W. Feller, Diffusion processes in genetics, in: Proc. 2 nd Berkeley Sympos. Math. Statist. and Probab., Univ. of California Press, 1951, 227-246.
  15. W. Feller, The parabolic differential equations and the associated semi-groups of transformations, Ann. of Math. 55 (1952), 468-519.
  16. W. Feller, Diffusion processes in one dimension, Trans. Amer. Math. Soc. 77 (1954), 1-31.
  17. T. Kato, Perturbation Theory for Linear Operators, Springer, 1966.
  18. A. Lupaş, Die Folge der Beta Operatoren, Dissertation, Universität Stuttgart, 1972.
  19. R. G. Mamedov, The asymptotic value of the approximation of differentiable functions by linear positive operators, Dokl. Akad. Nauk SSSR 128 (1959), 471-474 (in Russian).
  20. G. Metafune, Analyticity for some degenerate one-dimensional evolution equations, Studia Math. 127 (1998), 251-276.
  21. R. Nagel (ed.), One-Parameter Semigroups of Positive Operators, Lecture Notes in Math. 1184, Springer, Berlin, 1986.
  22. A. Pazy, Semigroups of Linear Operators and Applications to Partial Differential Equations, Springer, Berlin, 1983.
  23. B. Sendov and V. Popov, The Averaged Moduli of Smoothness, Pure Appl. Math., Wiley, 1988.
  24. N. Shimakura, Existence and uniqueness of solutions for a diffusion model of intergroup selection, J. Math. Kyoto Univ. 25 (1985), 775-788.
  25. C. A. Timmermans, On C0-semigroups in a space of bounded continuous functions in the case of entrance or natural boundary points, in: Approximation and Optimization, J. A. Gómez Fernández et al. (eds.), Lecture Notes in Math. 1354, Springer, Berlin, 1988, 209-216.
  26. H. F. Trotter, Approximation of semi-groups of operators, Pacific J. Math. 8 (1958), 887-919.
Pages:
117-139
Main language of publication
English
Received
1999-01-19
Accepted
2000-02-04
Published
2000
Exact and natural sciences