Uhlenbeck compactification as a Bridgeland moduli space

Abstract

Let $(X,H)$ be a smooth, projective, polarized surface over $\mathbb{C}$, and let $v\in K_{\mathrm{num}}(X)$ be a class of positive rank. We prove that for certain Bridgeland stability conditions $\sigma =(\mathcal{A},Z)$ "on the vertical wall" for $v$, the good moduli space $M^{\sigma }(v)$ parameterizing S-equivalence classes of $\sigma$-semistable objects of class $v$ in $\mathcal{A}$ is projective. Moreover, we construct a bijective morphism $M^{\mathrm{Uhl}}(v)\to M^{\sigma }(v)$ from the Uhlenbeck compactification of $\mu$-stable vector bundles.

38 pages