Table of Contents

2023-05-07 Sun

sheaves on $B \backslash G / B$

Signs and Orientations

Their Lagrangians are union of spheres. They want a trivial $\R$ bundle on the space, so that the direct sum of $\R$ with the tangent bundle is trivial. (well, sometimes, a bundle is stably trivial, you just need to give it more rooms).

We choose trivialization $t$ and $t'$ for the two 'augmented' Lagrangian (are they jet bundle?).

A capping Lagrangian path in the oriented Lagrangians Grassmannian. (so, do I choose orientation of my Lagrangians? I guess I did, since I have trivializations, and I can substract that trivial line bundle.)

A stable capping trivialization is a trivialization of the capping path $L_{p,t} \oplus \R$, that interpolate the original trivializations on the two strands.

OK, these are the data. How do I provides orientation for the moduli spaces then?

We map the upper half-plane to the target space. actually, it is a constant map (what?) to $p$, and we consider the trivial vector bundle $\pi_p^*(T_p M)$. We define the Cauchy-Riemann tuple. $\xi, \eta, D$

well, a determinant line is a kernel minus cokernel, taking determinants.

What is orientation?

If $L$ satisfies certain topological condition, then the moduli space of disks ending on $L$ is orientable.

But, how do we define the A-infinity structures? Why we count some disks with a negative sign? When we say we orient the 0-dim moduli space of the disks, that means plus-minus signs.