%0 Journal Article %T Commutative Hopf structures over a loop %A Hua-Lin Huang %A Gongxiang Liu %A Yu Ye %J Mathematics %D 2010 %I arXiv %X Let $k$ be an algebraically closed field of characteristic $p>0$. For a loop $\circlearrowleft$, denote its path coalgebra by $k\circlearrowleft$. In this paper, all the finite-dimensional commutative Hopf algebras over the sub coalgebras of $k\circlearrowleft$ are given. As a direct consequence, all the commutative infinitesimal groups $\mathcal{G}$ with dim$_{k}$Lie$(\mathcal{G})=1$ are classified. %U http://arxiv.org/abs/1002.0405v1