标题： D-瞬子微扰理论 显示英文标题

标题： D-instanton Perturbation Theory

摘要： D-瞬子世界体积理论包含描述瞬子集体坐标的开弦零模。 在D-瞬子背景中的通常微扰振幅由于这些零模的存在而受到红外发散的影响，通常的动量解析延拓方法不起作用，因为D-瞬子上的所有开弦态都严格携带零动量。 弦场理论非常适合处理这些问题。 然而我们发现由于鬼场中存在额外的零模而出现新的细微之处。 这导致了Siegel规范的失效，但一种与BV形式主义一致的不同规范固定使微扰理论变得有限且明确。 在每一阶，这除了从黎曼曲面模空间积分得到的结果外，还会产生额外的振幅贡献。 显示英文摘要

摘要： D-instanton world-volume theory has open string zero modes describing collective coordinates of the instanton. The usual perturbative amplitudes in the D-instanton background suffer from infra-red divergences due to the presence of these zero modes, and the usual approach of analytic continuation in momenta does not work since all open string states on a D-instanton carry strictly zero momentum. String field theory is well-suited for tackling these issues. However we find a new subtlety due to the existence of additional zero modes in the ghost sector. This causes a breakdown of the Siegel gauge, but a different gauge fixing consistent with the BV formalism renders the perturbation theory finite and unambiguous. At each order, this produces extra contribution to the amplitude besides what is obtained from integration over the moduli space of Riemann surfaces.