Hostname: page-component-76fb5796d-25wd4 Total loading time: 0 Render date: 2024-04-28T22:53:12.162Z Has data issue: false hasContentIssue false

AN ALTERNATIVE APPROACH TO FRÉCHET DERIVATIVES

Published online by Cambridge University Press:  14 May 2020

SHANE ARORA
Affiliation:
School of Mathematics & Statistics, University of Sydney, NSW 2006, Australia e-mail: saro0188@uni.sydney.edu.au
HAZEL BROWNE
Affiliation:
School of Mathematics & Statistics, University of Sydney, NSW 2006, Australia e-mail: hbro4811@uni.sydney.edu.au
DANIEL DANERS
Affiliation:
School of Mathematics & Statistics, University of Sydney, NSW 2006, Australia e-mail: daniel.daners@sydney.edu.au

Abstract

We discuss an alternative approach to Fréchet derivatives on Banach spaces inspired by a characterisation of derivatives due to Carathéodory. The approach allows many questions of differentiability to be reduced to questions of continuity. We demonstrate how that simplifies the theory of differentiation, including the rules of differentiation and the Schwarz lemma on the symmetry of second-order derivatives. We also provide a short proof of the differentiable dependence of fixed points in the Banach fixed point theorem.

Type
Research Article
Copyright
© 2020 Australian Mathematical Publishing Association Inc.

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

Communicated by W. Moors

References

Acosta, E. G. and Delgado, C. G., ‘Fréchet vs. Carathéodory’, Amer. Math. Monthly (4) 101 (1994), 332338.Google Scholar
Adams, J. F., ‘Vector fields on spheres’, Ann. of Math. (2) 75 (1962), 603632.Google Scholar
Amann, H. and Escher, J., Analysis. II (Birkhäuser, Basel, 2008).Google Scholar
Bartle, R. G. and Sherbert, D. R., Introduction to Real Analysis, 4th edn (John Wiley & Sons, Hoboken, NJ, 2011).Google Scholar
Botsko, M. W. and Gosser, R. A., ‘On the differentiability of functions of several variables’, Amer. Math. Monthly (9) 92 (1985), 663665.Google Scholar
Brezis, H., Functional Analysis, Sobolev Spaces and Partial Differential Equations, Universitext (Springer, New York, 2011).Google Scholar
Brooks, R. M. and Schmitt, K., The Contraction Mapping Principle and Some Applications, Electronic Journal of Differential Equations Monograph, 9 (Texas State University – San Marcos, Department of Mathematics, San Marcos, TX, 2009).Google Scholar
Cabrales, R. C. and Rojas-Medar, M. A., ‘Sobre la diferenciabilidad de funciones en espacios de Banach’, Rev. Integr. Temas Mat. (2) 24 (2006), 87100.Google Scholar
Carathéodory, C., Funktionentheorie. Band I (Birkhäuser, Basel, 1950).Google Scholar
Eckmann, B., ‘Stetige Lösungen linearer Gleichungssysteme’, Comment. Math. Helv. 15 (1943), 318339.Google Scholar
Fréchet, M., ‘Sur la notion de différentielle totale’, Nouv. Ann. (4) 12 (1912), 385403.Google Scholar
Hairer, E. and Wanner, G., Analysis by its History (Springer, New York, 2008).Google Scholar
Hale, J. K., Ordinary Differential Equations, Pure and Applied Mathematics, XXI (Wiley-Interscience, New York, 1969).Google Scholar
Henry, D., Geometric Theory of Semilinear Parabolic Equations, Lecture Notes in Mathematics, 840 (Springer, Berlin, 1981).Google Scholar
Kuhn, S., ‘The derivative à la Carathéodory’, Amer. Math. Monthly (1) 98 (1991), 4044.Google Scholar
Martínez de la Rosa, F., Cálculo Diferencial: Consideraciones Teóricas y Metodológicas (Universidad de Cádiz, Servicio de Publicaciones, Cádiz, 1998).Google Scholar
Pinzón, S. and Paredes, M., ‘La derivada de Carathéodory en ℝ2 ’, Rev. Integr. Temas Mat. (2) 17 (2003), 6598.Google Scholar
Rudin, W., Principles of Mathematical Analysis, 3rd edn, International Series in Pure and Applied Mathematics (McGraw-Hill, New York, 1976).Google Scholar
Stolz, O., Grundzüge der Differential- und Integralrechnung. Erster Teil: Reelle Veränderliche und Functionen (B. G. Teubner, Leipzig, 1893).Google Scholar
Taylor, A. E. and Lay, D. C., Introduction to Functional Analysis, 2nd edn (John Wiley & Sons, New York, 1980).Google Scholar