Title: Strange duality on rational surfaces II: higher rank cases,
Abstract: We study Le Potier's strange duality conjecture on a rational surface. We
focus on the strange duality map $SD_{c_n^r,L}$ which involves the moduli space
of rank $r$ sheaves with trivial first Chern class and second Chern class $n$,
and the moduli space of 1-dimensional sheaves with determinant $L$ and Euler
characteristic 0. We show there is an exact sequence relating the map
$SD_{c_r^r,L}$ to $SD_{c^{r-1}_{r},L}$ and $SD_{c_r^r,L\otimes K_X}$ for all
$r\geq1$ under some conditions on $X$ and $L$ which applies to a large number
of cases on $\p^2$ or Hirzebruch surfaces . Also on $\mathbb{P}^2$ we show that
for any $r>0$, $SD_{c^r_r,dH}$ is an isomorphism for $d=1,2$, injective for
$d=3$ and moreover $SD_{c_3^3,rH}$ and $SD_{c_3^2,rH}$ are injective. At the
end we prove that the map $SD_{c_n^2,L}$ ($n\geq2$) is an isomorphism for
$X=\mathbb{P}^2$ or Fano rational ruled surfaces and $g_L=3$, and hence so is
$SD_{c_3^3,L}$ as a corollary of our main result.