Familty of Lagrangian submanifolds
1 Families with the structure of vector bundle
1.1 A subset of with additional structure
- Every Lagrangian submanifold comes with a subspace of functions on it:(in our application this subspace will be finite-dimensional)
- There is an action of on this subspace, more precisely for each we are given a linear map :such that
1.2 Continuation problem
- For every fixed , the extended functions are all in involution w.r.to the odd Poisson bracket on :(but for two different and in , the functions extended from are not required to be in involution from the functions extended from )
- The extension commutes with the action of diffeomorphisms:
Suppose that the answer is “yes”. Then we can enlarge to a larger subset of which has a structure of a vector bundle over , as we will now describe.
1.3 A vector bundle over
We define as the total space of the following vector bundle over : the fiber over is the orbit of under the Hamiltonian vector fields generated by all the Hamiltonians from .
Instead of the elements of being in involution with each other, we could have required that the space is closed under the Poisson bracket. But then would not be a vector bundle, just some nonlinear bundle.
is diffeomorphism-invariant
2 Application to RNS formalism
2.1 Base family
2.2 Subspaces
2.3 Are there solutions to continuation problem?
We do not have an explicit solution of the continuation problem. Actually, we do not even have a proof that the solution exists.
2.4 Split family
The requirement of diffeomorphism-invariance in the continuation problem was crucial for us, because it guarantees the action of the mapping class group on our cycle.