玻色弦理论中由S矩阵元导出的快子耦合
Tachyon couplings from S-matrix elements in bosonic string theory
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中文总结 AI 辅助
该研究提出玻色弦理论中构造有效作用量的系统框架，明确快子耦合的选择规则，通过圆盘级振幅验证其与0型理论的一致性，契合相关对偶性。
中文摘要 AI 辅助
我们引入了一种用于构造玻色弦理论中时空与D膜有效作用量的系统框架，该框架涵盖了快子和无质量模式。这些作用量需满足规范不变性，并与球面级和圆盘级S矩阵元的展开相容。我们的核心主张规定，对于每个闭弦或开弦道，涉及奇数个快子的S矩阵极点必须通过有效作用量的展开来重现，而涉及偶数个快子的极点则必须精确匹配。这一准则施加了严格的选择规则：体作用量仅包含闭弦快子场的偶次幂，D膜作用量仅包含开弦快子场的偶次幂。相比之下，闭弦快子与D膜的耦合约束较少，允许偶次和奇次场多重性。作为具体应用，我们分析了包含两个闭弦快子的圆盘级振幅，并证明所得的线性和二次快子-D膜相互作用与0型理论的对应相互作用完全一致，这与0型理论的轨形和玻色弦理论在\boldsymbol{T^{16}}上的紧化之间的对偶性相符。
英文摘要
We introduce a systematic framework for constructing spacetime and D-brane effective actions in bosonic string theory, encompassing both tachyon and massless modes. The actions are required to be gauge invariant and compatible with the expansion of sphere- and disk-level S-matrix elements. Our central proposal stipulates that, for each closed- or open-string channel, S-matrix poles involving an odd number of tachyons must be reproduced via an expansion in the effective action, whereas those with an even number of tachyons must be matched exactly. This criterion imposes strong selection rules: the bulk action contains only even powers of closed-string tachyon fields, and the D-brane action only even powers of open-string tachyon fields. In contrast, couplings of closed-string tachyons to D-branes are less constrained and allow both even and odd field multiplicities. As a concrete application, we analyze the disk-level amplitude involving two closed-string tachyons and demonstrate that the resulting linear and quadratic tachyon-D-brane interactions coincide precisely with those of type 0 theory. This is consistent with the duality between the orbifold of type 0 theory and the compactification of bosonic string theory on \(T^{16}\).
