We prove a characterization of the injective linear transformations on real vector spaces: Let XX and YY be an mm-dimensional and an nn-dimensional real vector spaces (n≥m≥2)(n \geq m \geq 2), respectively. Assume that a mapping f ⁣:X→Yf \colon X \to Y satisfies dimf(X)≥2{\rm dim} f(X) \geq 2 and f(o)=of(o) = o, where oo denotes the origin of XX and YY. Then, ff is an injective linear transformation if and only if ff maps every line in XX onto a (corresponding) line in YY and preserves the ordering on line.

Contact details are reproduced from the original publication and may be historical.

Soon-Mo Jung

Mathematics Section, College of Science and Technology, Hongik University, 339-701 Jochiwon, Republic of Korea

smjung@hongik.ac.kr
  1. I. J. Bakelman: Convex Analysis and Nonlinear Geometric Elliptic Equations, Springer, Berlin (1994).https://doi.org/10.1007/978-3-642-69881-1Google Scholar
  2. M. Berger, P. Pansu, J. P. Berry, X. Saint-Raymond: Problems in Geometry, Springer, New York (1984).https://doi.org/10.1007/978-1-4757-1836-2Google Scholar
  3. P. J. Kelly, M. L. Weiss: Geometry and Convexity. A Study in Mathematical Methods, Wiley, New York (1979).Google Scholar
  4. S. R. Lay: Convex Sets and Their Applications, Wiley, New York (1982).Google Scholar
  5. H. Schaal: Lineare Algebra und Analytische Geometrie. Band 1, Vieweg, Braunschweig (1976).Google Scholar

S.-M. Jung. “A Characterization of Injective Linear Transformations.” Journal of Convex Analysis 17 (2010), No. 1, 293–299. https://doi.org/10.68381/jca17021