Analytic Solutions of Special Functional Equations

Main Article Content

Octav Olteanu

Abstract

We recall some of our earlier results on the construction of a mapping defined implicitly, without using the implicit function theorem. All these considerations work in the real case, for functions and operators. Then we consider the complex case, proving the analyticity of the function defined implicitly, under certain hypothesis. Some consequences are given. An approximating formula for the analytic form of the solution is also given. Finally, one illustrates the preceding results by an application to a concrete functional and operatorial equation. Some related examples are given.

Article Details

References

  1. Colojoară, I. Elements of Spectral Theory, Academiei, 1968 (in Romanian).
  2. Cristescu, R., Ordered Vector Spaces and Linear Operators, Academiei, Bucharest, and Abacus Press, Tunbridge Wells, Kent, 1976.
  3. Needham, T., Visual complex analysis, Clarendon Press, Oxford, 1997.
  4. Olteanu, A. & Olteanu, O., Solving some special functional equations by a general “geometrical” method, and an approach to the complex case, Revue Roumaine de Mathématiques Pures et Appliquées, 51, 5-6 (2006), 735-745.
  5. Olteanu, O. & Simion, Gh., A new geometric aspect of the implicit function principle and Newton's method for operators, Math. Reports, 5(55), 1 (2003), 61-84.
  6. Olteanu O. & Radu, C., Solving some functional and operatorial equations by a general constructive method, U.P.B. Sci. Bull., Series A, 69, 4 (2007), 57-66.
  7. Olteanu, O., Geometric aspects in operator theory and applications, Lambert Academic Publishing, Saarbrücken, 2012.
  8. Rudin, W., Real and Complex Analysis. Third Edition, McGraw-Hill, Inc., 1987.