论文标题
开放式弦乐场理论的经典宇宙学常数
The classical cosmological constant of open-closed string field theory
论文作者
论文摘要
我们考虑了由骨器开放式字符串字段理论框架中的封闭字符串背景变化引起的D-Brane系统的变形，在该框架的框架中，可以明确地驯服来自开放式和封闭的字符串退化的红外差异。一个封闭的弦乐经典解会导致开放字符串的t t thift绕弦真真空，并生成由两个术语组成的宇宙常数：一个与封闭的弦溶液直接相关，另一个取决于开放的字符串真空移动。我们表明，在封闭的SFT仪表转换下，这两个术语的总和仅是不变的，因此是可观察到的。我们猜想，这种可观察到的可观察到的与世界表磁盘分区的变化是普遍成比例的，在未构造的背景下的启动d-brane与变形背景中的最终d-brane之间，这通常还包括字符串耦合常数的变化。我们通过考虑描述Narain紧凑型变形的扰动闭合弦溶液来测试猜想，并且从SFT宇宙常数中，我们重现了生活在紧凑型中的各种D-Branes的$ G $功能中的预期变化。在此过程中，我们还能够确定变形中二阶的字符串耦合常数的令人惊讶的变化。
We consider deformations of D-brane systems induced by a change in the closed string background in the framework of bosonic open-closed string field theory, where it is possible to unambiguously tame infrared divergences originating from both open and closed string degenerations. A closed string classical solution induces a tadpole for the open strings which shifts the open string vacuum and generates a cosmological constant composed of two terms: one which is directly related to the closed string solution and the other which depends on the open string vacuum shift. We show that only the sum of these two terms is invariant under closed SFT gauge transformations and therefore is an observable. We conjecture that this observable is universally proportional to the shift in the world-sheet disk partition function between the starting D-brane in undeformed background and the final D-brane in deformed background, which typically includes also a change in the string coupling constant. We test the conjecture by considering a perturbative closed string solution describing deformations of a Narain compactification and, from the SFT cosmological constant, we reproduce the expected shift in the $g$-function of various D-branes living in the compactification. In doing this we are also able to identify a surprising change in the string coupling constant at second order in the deformation.
