论文标题
Abel-Jacobi地图和拉回度量的曲率
Abel-Jacobi map and curvature of the pulled back metric
论文作者
论文摘要
令$ x $为紧凑的连接的riemann属,至少两个。 Abel-Jacobi Map $φ:{\ rm sym}^d(x)\ rightarrow {\ rm pic}^d(x)$是嵌入的,如果$ d $小于$ x $的gonity。我们研究了$ {\ rm pic}^d(x)$的flat衡量标准的下拉背包的曲率。特别是,我们表明,当$ d = 1 $时,如果$ x $不是过度纤维化的,则曲率是严格的负面负数,而当$ x $是过度纤维化的时,曲率是非阳性的,并且完全消失在因$ x $的点上而消失的$ x $。
Let $X$ be a compact connected Riemann surface of genus at least two. The Abel-Jacobi map $φ: {\rm Sym}^d(X) \rightarrow {\rm Pic}^d(X)$ is an embedding if $d$ is less than the gonality of $X$. We investigate the curvature of the pull-back, by $φ$, of the flat metric on ${\rm Pic}^d(X)$. In particular, we show that when $d=1$, the curvature is strictly negative everywhere if $X$ is not hyperelliptic, and when $X$ is hyperelliptic, the curvature is nonpositive with vanishing exactly on the points of $X$ fixed by the hyperelliptic involution.