On the Semistability of certain Lazarsfeld-Mukai bundles on Abelian surfaces

Abstract

Let $X$ be the Jacobian of a genus 2 curve $\widetilde{\mathcal{C}}$ over $\mathbb{C}$ and $Y$ be the associated Kummer surface. Consider an ample line bundle $L=O(m\widetilde{\mathcal{C}})$ on $X$ for an even number $m$, and its descent to $Y$, say $L'$. We show that any dominating component of $\mathcal{W}^1_{d}(|L'|)$ corresponds to $\mu_{L'}$-stable Lazarsfeld-Mukai bundles on $Y$. Further, for a smooth curve $C \in |L|$ and a base-point free $g^1_d$ on $C$, say $(A,V)$, we study the $\mu_L$-semistability of the rank-2 Lazarsfeld-Mukai bundle associated to $(C,(A,V))$ on $X$. Under certain assumptions on $C$ and the $g^1_d$, we show that the above Lazarsfeld-Mukai bundles are $\mu_L$-semistable.