论文标题
脱壳弦I：S-Matrix和动作
Off-Shell Strings I: S-matrix and Action
论文作者
论文摘要
我们解释了为什么Tseytlin的弦理论的脱壳表述明确定义。尽管量化壳背景上的字符串需要任意选择Weyl框架，但是这种选择并不具有物理上的显着性，因为它可以吸收到目标空间场的场中重新定义。 The off-shell formalism is particularly subtle at tree-level, due to the treatment of the noncompact conformal Killing group SL(2,$\mathbb{C}$) of the sphere.我们证明Tseytlin的Sphere处方会恢复标准树级Lorentzian S-Matrix，并展示如何从世界表格上的UV截止中提取弦乐$ i \ varepsilon $处方。我们还证明，在$ g_s $和$α^{\ prime} $中，获得了正确的树级运动方程，并阐明了字符串动作与C理论之间的密切连接。
We explain why Tseytlin's off-shell formulation of string theory is well-defined. Although quantizing strings on an off-shell background requires an arbitrary choice of Weyl frame, this choice is not physically significant since it can be absorbed into a field redefinition of the target space fields. The off-shell formalism is particularly subtle at tree-level, due to the treatment of the noncompact conformal Killing group SL(2,$\mathbb{C}$) of the sphere. We prove that Tseytlin's sphere prescriptions recover the standard tree-level Lorentzian S-matrix, and show how to extract the stringy $i\varepsilon$ prescription from the UV cutoff on the worldsheet. We also demonstrate that the correct tree-level equations of motion are obtained to all orders in perturbation theory in $g_s$ and $α^{\prime}$, and illuminate the close connection between the string action and the c-theorem.
