| | | Fixed points |
The last one of the fundamental concepts induced by an action of G on X is that of fixed points . A point x ÎX is said to be fixed under g ÎG if and only if gx=x, and the set of all the fixed points of g is indicated by
Xg := {x | gx=x }.
More generally, for any subset S ÍG, we put
XS := {x | " g ÎS : gx=x }.
The particular case XG is called the set of invariants .
| harald.fripertinger "at" uni-graz.at | http://www-ang.kfunigraz.ac.at/~fripert/ | UNI-Graz | Institut für Mathematik | UNI-Bayreuth | Lehrstuhl II für Mathematik |
| | | Fixed points |