ترغب بنشر مسار تعليمي؟ اضغط هنا

A remark on a conjecture of Hain and Looijenga

269   0   0.0 ( 0 )
 نشر من قبل Carel Faber
 تاريخ النشر 2012
  مجال البحث
والبحث باللغة English
 تأليف Carel Faber




اسأل ChatGPT حول البحث

After recalling the various tautological algebras of the moduli space of curves and some of its partial compactifications and stating several well-known results and conjectures concerning these algebras, we prove that the natural extension to the case of pointed curves of a 1996 conjecture of Hain and Looijenga is true if and only if two of the stated conjectures are true.

قيم البحث

اقرأ أيضاً

We present algebraic and geometric arguments that give a complete classification of the rational normal scrolls that are hyperplane section of a given rational normal scrolls.
73 - Fumiaki Suzuki 2018
A classical question asks whether the Abel-Jacobi map is universal among all regular homomorphisms. In this paper, we prove that we can construct a $4$-fold which gives the negative answer in codimension $3$ if the generalized Bloch conjecture holds for a $3$-fold constructed by Colliot-Thel`ene and Voisin in the context of the study of the defect of the integral Hodge conjecture in degree $4$.
136 - Vincenzo Di Gennaro 2019
Let $C$ be an irreducible, reduced, non-degenerate curve, of arithmetic genus $g$ and degree $d$, in the projective space $mathbf P^4$ over the complex field. Assume that $C$ satisfies the following {it flag condition of type $(s,t)$}: {$C$ does not lie on any surface of degree $<s$, and on any hypersurface of degree $<t$}. Improving previous results, in the present paper we exhibit a Castelnuovo-Halphen type bound for $g$, under the assumption $sleq t^2-t$ and $dgg t$. In the range $t^2-2t+3leq sleq t^2-t$, $dgg t$, we are able to give some information on the extremal curves. They are arithmetically Cohen-Macaulay curves, and lie on a flag like $Ssubset F$, where $S$ is a surface of degree $s$, $F$ a hypersurface of degree $t$, $S$ is unique, and its general hyperplane section is a space extremal curve, not contained in any surface of degree $<t$. In the case $dequiv 0$ (modulo $s$), they are exactly the complete intersections of a surface $S$ as above, with a hypersurface. As a consequence of previous results, we get a bound for the speciality index of a curve satisfying a flag condition.
108 - Jinsong Xu 2019
We improve a result of Prokhorov and Shramov on the rank of finite $p$-subgroups of the birational automorphism group of a rationally connected variety. Known examples show that they are sharp in many cases.
We prove a Hochschild-Kostant-Rosenberg decomposition theorem for smooth proper schemes $X$ in characteristic $p$ when $dim Xleq p$. The best known previous result of this kind, due to Yekutieli, required $dim X<p$. Yekutielis result follows from the observation that the denominators appearing in the classical proof of HKR do not divide $p$ when $dim X<p$. Our extension to $dim X=p$ requires a homological fact: the Hochschild homology of a smooth proper scheme is self-dual.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا