I have a naive question:(I saw that it is related to relative K-theory of Hodge-Deligne and also Nadel-Chern-Weil theory )
Let $\mathcal M (r, d)$ be the moduli space of stable vector bundles of rank $r$ with a fixed determinant of degree $d$ on a projective variety $X$. Then when the Albanese map $\mathcal M (r, d)\to Alb(\mathcal M (r, d))$ is surjective.?