This is an announcement for the paper "The complex angle in normed spaces" by Volker W. Thurey.
Abstract: We consider a generalized angle in complex normed vector spaces. Its definition corresponds to the definition of the well known Euclidean angle in real inner product spaces. Not surprisingly it yields complex values as `angles'. This `angle' has some simple properties, which are known from the usual angle in real inner product spaces. But to do ordinary Euclidean geometry real angles are necessary. We show that even in a complex normed space there are many pure real valued `angles'. The situation improves yet in inner product spaces. There we can use the known theory of orthogonal systems to find many pairs of vectors with real angles, and to do geometry which is based on the Greeks 2000 years ago.
Archive classification: math.FA
Mathematics Subject Classification: 46B20, 46C05, 30E99
Remarks: 21 pages
Submitted from: volker@thuerey.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1308.5412
or