论文标题
曲线正交捆绑包的各向同性引用方案
Isotropic Quot schemes of orthogonal bundles over a curve
论文作者
论文摘要
我们研究各向同性引号方案$ iq_e(v)$参数化度量$ e $ $ $ y $ y $ shosotropic子仓库的最大等级是曲线正交束$ v $的最大等级。方案$ iq_e(v)$包含空间的紧凑型$ iq^o_e(v)度的$ e $ e $ e $最大的各向同性分支,但行为与经典报价方案和[6]中的Lagrangian Quot Scheme的行为差异很大。我们观察到,对于某些拓扑类型的$ v $,计划$ iq_e(v)$对于所有$ e $都是空的。在其余的情况下,对于无限的许多$ e $,完全由不饱和子份额组成的$ iq_e(v)$的不可约组件,因此$ iq_e(v)$严格大于$ iq^o_e(v)$的$ iq_e(v)$。作为我们的主要结果,我们证明,对于任何正交包$ v $,对于$ e \ ll 0 $,closure $ \ overline {iq^o_e(v)$ of $ iq^o_e(v)$是空的,或者是一个或两个不可固定的连接组件,取决于$°(v)$ $ $。这样做,我们还表征了$ \ overline {iq^o_e(v)} $的不饱和部分时,$ v $甚至排名。
We study the isotropic Quot schemes $IQ_e (V)$ parameterizing degree $e$ isotropic subsheaves of maximal rank of an orthogonal bundle $V$ over a curve. The scheme $IQ_e (V)$ contains a compactification of the space $IQ^o_e (V)$ of degree $e$ maximal isotropic subbundles, but behaves quite differently from the classical Quot scheme, and the Lagrangian Quot scheme in [6]. We observe that for certain topological types of $V$, the scheme $IQ_e (V)$ is empty for all $e$. In the remaining cases, for infinitely many $e$ there are irreducible components of $IQ_e (V)$ consisting entirely of nonsaturated subsheaves, and so $IQ_e (V)$ is strictly larger than the closure of $IQ^o_e (V)$. As our main result, we prove that for any orthogonal bundle $V$ and for $e \ll 0$, the closure $\overline{IQ^o_e (V)}$ of $IQ^o_e (V)$ is either empty or consists of one or two irreducible connected components, depending on $°(V)$ and $e$. In so doing, we also characterize the nonsaturated part of $\overline{IQ^o_e (V)}$ when $V$ has even rank.