Let $ \mathcal{M}$ be the moduli stacks of vector bundles of degree $ 0$ and rank $ n$ over smooth curve $ X$ , $ \mathcal{M}_{\mathcal{O}}$ be the moduli stack of vector bundles with fixed determinant $ \mathcal{O}$ and $ J$ be the stacks of line bundles of degree $ 0$ on X. There isRead more