论文标题
模棱两可的皮卡德组和劳伦特多项式
Equivariant Picard groups and Laurent polynomials
论文作者
论文摘要
令$ g $为有限的组。对于$ g $ -ring $ a，$ let $ {\ rm pic}^{\ it g}（{\ it a}）$表示$ A的equivariant picard组。有收缩$ h_ {et}^{1}（g; spec（a），\ mathbb {z}）。$这给出了组$ {\ rm pic}^{\ it g}的自然分解
Let $G$ be a finite group. For a $G$-ring $A,$ let ${\rm Pic}^{\it G}({\it A})$ denote the equivariant Picard group of $A.$ We show that if $A$ is a finite type algebra over a field $k$ then ${\rm Pic}^{\it G}({\it A})$ is contracted in the sense of Bass with contraction $H_{et}^{1}(G; Spec(A), \mathbb{Z}).$ This gives a natural decomposition of the group ${\rm Pic}^{\it G}({\it A[t, t^{-1}]}).$
