AI 中文总结
本文证明Russell三次三维簇的柱体是柔性的,通过构造四个显式代数$\mathbb G_a$-作用生成可递群,从而建立其柔性性质。
AI 中文摘要
Russell三次三维簇是由$x^2y+z^2+x+t^3=0$定义的超曲面$\mathcal X\subset\mathbb A^4_{\mathbb C}$。我们证明其柱体$\mathcal X\times\mathbb A^1$是柔性的。更精确地说,在将其在$\mathbb A^5$中的标准嵌入替换为等价嵌入后,我们构造了环境仿射空间上的四个显式代数$\mathbb G_a$-作用,这些作用的限制生成一个在柱体上可递作用的群。
英文摘要
The Russell cubic threefold is the hypersurface $\mathcal X\subset\mathbb A^4_{\mathbb C}$ defined by $x^2y+z^2+x+t^3=0$. We prove that its cylinder $\mathcal X\times\mathbb A^1$ is flexible. More precisely, after replacing its standard embedding in $\mathbb A^5$ by an equivalent one, we construct four explicit algebraic $\mathbb G_a$-actions on the ambient affine space whose restrictions generate a group acting transitively on the cylinder.