论文标题
某些普遍家族的双方四倍的普遍家庭的不合理性
Unirationality of certain universal families of cubic fourfolds
论文作者
论文摘要
此简短说明的目的是在其模量空间的某些基因座上定义\ it Universion Cubic四倍\ rm。然后,我们提出了两种方法,以证明它在Hassett Divisors $ \ Mathcal {C} _d $的范围内是不合理的,$ 8 \ leq d \ leq d \ leq 42 $。通过归纳性应用此参数,我们能够证明,在相同的值范围内,$ \ Mathcal {C} _ {d,n} $对于所有$ n $的整数值都是Urirations。最后,我们观察到,对于$ d $的明显无限值,$ \ $ \ mathcal {c} _d $超过$ d $的值不可能是Urirational。
The aim of this short note is to define the \it universal cubic fourfold \rm over certain loci of their moduli space. Then, we propose two methods to prove that it is unirational over the Hassett divisors $\mathcal{C}_d$, in the range $8\leq d \leq 42$. By applying inductively this argument, we are able to show that, in the same range of values, $\mathcal{C}_{d,n}$ is unirational for all integer values of $n$. Finally, we observe that for explicit infinitely many values of $d$, the universal cubic fourfold over $\mathcal{C}_d$ can not be unirational.