A note on Griffiths infinitesimal invariant for curves
Emanuele Raviolo
备注：
revised version according to referee's suggestions. Annali di Matematica Pura e Applicata 2012; the final publication is available at http://www.springerlink.com
Given a generic curve of genus $g\geqslant4$ and a smooth point $L\in W_{g-1}^{1}(C)$, whose linear system is base-point free, we consider the Abel-Jacobi normal function associated to $L^{\otimes 2}\otimes ω_{C}^{-1}$, when $(C,L)$ varies in moduli. We prove that its infinitesimal invariant reconstruct the couple $(C,L)$. When $g=4$, we obtain the generic Torelli theorem proved by Griffiths.
We calculate a Griffiths-type ring for smooth complete intersection in Grassmannians. This is the analogue of the classical Jacobian ring for complete intersections in projective space, and allows us to explicitly compute their Hodge groups.
Let $ (E,h) $ be a Griffiths semipositive Hermitian holomorphic vector bundle of rank $ 3 $ over a complex manifold. In this paper, we prove the positivity of the characteristic differential form $ c_1(E,h) \wedge c_2(E,h) - c_3(E,h) $, thus providing a new evidence towards a conjecture by Griffiths about the positivity of the Schur polynomials in the Chern forms of Griffiths semipositive vector bundles. As a consequence, we establish a new chain of inequalities between Chern forms. Moreover, we point out how to obtain the positivity of the second Chern form $ c_2(E,h) $ in any rank, starting …
光滑代数簇X上的余维p代数圈模有理等价的Chow群坚决地抵制了代数几何学家们对它们结构的探索。这本书探讨了一个“线性化”的方法来解决这个问题，重点是无穷小结构的周组附近的身份元素。马克·格林和菲利普·格里菲思最近的工作对这种方法作了初步的描述。Bloch、Stienstra、Hesselholt、Van der Kallen和其他人也探讨过类似的主题。Bloch的一个著名公式将Chow群表示为X上代数K理论层的Zapriki层上同调群。因此，Chow群的“线性化”与代数K理论的“线性化”有关，后者可以用负循环同调来描述。从这种方法中产生的“适当的形式构造”是一个“机器”，涉及到从X上的四个不同的广义上同调理论中产生的coniveau谱序列，最后两个序列由代数陈特征符连接。由于coniveau过滤的关键作用，我把这种结构称为coniveau机器。主要定理在这本书中建立了存在的coniveau机的代数K理论上顺利代数品种。一个直接推论是Chow群的广义切群用负循环同调表示的一个新公式。
The parity of theta characteristics is preserved by infinitesimal deformations
Fundação para a Ciência e Tecnologia (FCT), Portugal, through CAMGSD, IST-ID（葡萄牙科学与技术基金会（FCT），通过CAMGSD，IST-ID）；European Union - Next Generation EU, Mission 4 Component 2（欧盟-下一代欧盟，使命4组成部分2）；Italian MUR（意大利教育部大学与研究部）；Centro de Análise Matemática, Geometria e Sistemas Dinâmicos（数学分析、几何与动力系统中心）；INDAM（意大利国家高等研究学院数学研究所）
We determine the second fundamental form of a variation of Hodge Structure of a smooth projective hypersurface using the classical identification of the Hodge structure and the action of the infinitesimal variation of Hodge structure with pieces of the Jacobian Ideal of the hypersurface. This simple algebraic description also implies that, in this case, the variation of Hodge structure satisfies a new set of second order partial differential equations.Comments are welcome!
