标题： 斯特雷贝尔微分和弦场理论 显示英文标题

标题： Strebel differentials and string field theory

摘要： 一个具有$g$亏格和$n$个刺孔的闭弦世界面可以表示为一种接触相互作用，其中$n$个半无限圆柱体通过在其上的Strebel微分以特定方式粘合在一起，如果$n\geq1,\ 2g-2+n>0$。 我们构建了一个闭弦的弦场理论，使得所有的费曼图都由这样的接触相互作用表示。 为了做到这一点，我们使用组合Fenchel-Nielsen坐标来描述模空间，在基础弦理论中定义了离壳振幅，并推导出了它们满足的递归关系。 利用Fokker-Planck形式，我们构建了一个弦场理论，通过Schwinger-Dyson方程可以从中推导出该递归关系。 Fokker-Planck哈密顿量包括动能项和三个弦相互作用项。 显示英文摘要

摘要： A closed string worldsheet of genus $g$ with $n$ punctures can be presented as a contact interaction in which $n$ semi-infinite cylinders are glued together in a specific way via the Strebel differential on it, if $n\geq1,\ 2g-2+n>0$. We construct a string field theory of closed strings such that all the Feynman diagrams are represented by such contact interactions. In order to do so, we define off-shell amplitudes in the underlying string theory using the combinatorial Fenchel-Nielsen coordinates to describe the moduli space and derive a recursion relation satisfied by them. Utilizing the Fokker-Planck formalism, we construct a string field theory from which the recursion relation can be deduced through the Schwinger-Dyson equation. The Fokker-Planck Hamiltonian consists of kinetic terms and three string interaction terms.