Abstract
We introduce the notion of skeleton with a head in a non-zero real vector space. We prove that skeletons with a head describe order unit spaces geometrically. Next, we prove that the skeleton consists of boundary elements of the positive cone of norm one. We discuss some elementary properties of the skeleton. We also find a condition under which V contains a copy of \(\ell _{\infty }^n\) for some \(n \in {\mathbb {N}}\) as an order unit subspace.
Similar content being viewed by others
References
Alfsen, E.M.: Compact Convex Sets and Boundary Integrals. Springer, Berlin (1971)
Asimov, L.: Well-capped convex cones. Pac. J. Math. 26, 421–431 (1968)
Bonsall, F.F.: Endomorphisms of a partially ordered space without order unit. J. Lond. Math. Soc. 30, 144–153 (1955)
Choi, M.D., Effros, E.G.: Injectivity and operator spaces. J. Funct. Anal. 24, 156–209 (1977)
Edwards, D.A.: Homeomorphic affine embedding of a locally compact cone into a Banach space endowed with vague topology. Proc. Lond. Math. Soc. 14, 399–414 (1964)
Ellis, A.J.: The duality of partially ordered normed linear spaces. J. Lond. Math. Soc. 39, 730–744 (1964)
Ghatak, A., Karn, A.K.: Quantization of \(A_0(K)\) spaces. Oper. Matrices 14(2), 381–399 (2020)
Jameson, G.J.O.: Ordered Linear Spaces. Lecture Notes in Mathematics. Springer, Berlin (1970)
Kadison, R.V.: Order properties of bounded self-adjoint operators. Proc. Am. Math. Soc. 2(3), 505–510 (1951)
Kadison, R.V.: A representation theory for commutative topological algebras. Mem. Am. Math. Soc. 7 (1951)
Karn, A.K.: Orthogonality in \(\ell _p\)-spaces and its bearing on ordered Banach spaces. Positivity 18(2), 223–234 (2014)
Karn, A.K.: Algebraic orthogonality and commuting projections in operator algebras. Acta Sci. Math. (Szeged) 84, 323–353 (2018)
Karn, A.K.: Order units in normed linear spaces. Preprint
Ng, K.-F.: The duality of partially ordered Banach spaces. Proc. Lond. Math. Soc. 19, 268–288 (1969)
Sherman, S.: Order in operator algebras. Am. J. Math. 73(1), 227–232 (1951)
Acknowledgements
The author is grateful to the referee for valuable suggestions. The author was partially supported by Science and Engineering Research Board, Department of Science and Technology, Government of India sponsored Mathematical Research Impact Centric Support project (reference no. MTR/2020/000017).
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by Enrique A. Sanchez Perez.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Karn, A.K. On the geometry of an order unit space. Adv. Oper. Theory 9, 28 (2024). https://doi.org/10.1007/s43036-024-00327-8
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s43036-024-00327-8