Symplectic leaves
imported>Pythagoras0님의 2020년 11월 13일 (금) 06:47 판
introduction
- symplectic geometry
- The symplectic leaves are equivalence relations \(x \sim y\) if and only if \(x\) can be connected to \(y\) be a piece-wise Hamiltonian path
- Let \(D\) be a degenerate distribution
- this means that for every point \(x \in M\), \(D_x\) is a subset of \(T_x M\)
- subset = subspace
- distribution normally means that \(D_x\) is constant rank
- and \(D_x\) is spanned by vector fields
- which means that for every \(x\) there is vector fields \(X_1,\ldots,X_r\) locally defined around \(x\) such that \(X_1(x),\ldots,X_r(x)\) span \(D_x\)
- and \(X_1(y),\ldots,X_r(y)\) lie in \(D_y\) for all \(y\) where they are defined
- a foliation of \(D\) is an immersed manifold \(A\) of \(M\) with \(TA = D\)
- Let \(M^{dis}\) be the manifold with underlying set \(M\) and the discrete topology
- \(M^{dis}\) is an immersed manifold for \(D = M \times 0\)
- \(M = \R^2\)
- \(D = \R^2 \times \R\)
- the foliation is the map \(\bigcup_{\R} \R \rightarrow \R^2\)