let \(\CritVal(W)\subset C\) be the subset of critical values of \(W\). For each \(c\in \CritVal(W)\), we have a ``smaller'' Landau-Ginzburg model \(Y_c\) by trivially extending the \(W^{-1}(B(c, \eps))\to B(c, \eps)\) to a fibration over \(\CC\).
Define \(\FS_c=\FS(Y_v, W)\).
definition 0.0.2
Let \(c \in \CritVal(W)\) be a critical point. A vanishing path for \(c\) is a path \(\gamma: [0, \infty) \to \CC\) such that
\(\gamma(0) = c\)
\(\gamma\) avoids all other critical values
\(\gamma(t) = t\) for \(t \gg 0\).
A vanishing path determines an embedding \(\FS_c\into \FS(Y, W)\) by extending Lagrangian submanifolds over the vanishing path using symplectic parallel transport.
If we choose ``disjoint'' vanishing paths, we get a semi-orthogonal decomposition.
\[\FS(Y, W) = \langle FS_1, \ldots, FS_n\rangle \]
example 0.0.4
Consider the symplectic Landau-Ginzburg model whose critical points are arranged as follows:
We obtain a semi-orthogonal decomposition \(\FS(Y, W) = \langle \FS_1, \FS_2, \FS_3 \rangle\).