Diffeomorphism
Flow on a manifold
Let π be a πΆπΌ-manifold with group of diffeomorphisms AutπΌβ‘(π).
A (local) 1-parameter group π? :β βAutπΌβ‘(π) is called a (local) flow on π. diff
The orbit of a point π βπ defines a πΆπΌ-curve
πΎ=π?(π):(πβ,π+)βπ
with πΎ(0) =π.
The map
πβ¦ΛπΎ(0)=ddπ‘ππ‘(π)β£π‘=0
defines a πΆπΌ-vector field π£π βπ(π), called the infinitesimal generator of π?.
Conversely, given a vector field π£π βπ(π), one can (usually) find a corresponding local flow whose orbits are called integral curves.
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