Form factor perturbation theory from finite volume
Form factor perturbation theory from finite volume
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有限体积的形状因子摄动理论
DOI：
10.1016/j.nuclphysb.2009.10.001
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
G. Takács
中科院分区：
文献类型：
--
作者：
G. Takács
通过将系统置于有限体积中进行正则化，我们发展了一种新的方法来研究不可积模型的形状因子微扰理论，这种不可积模型被描述为可积模型的微扰。这允许超越第一阶的形状因子微扰理论，并在原则上适用于任何阶。该程序进行了详细的双sine-Gordon理论，真空能量密度和呼吸质量校正在二阶评估。所得结果与截断共形空间法所得结果一致。正则化过程也可以用于计算涉及不连续的形状因子的其他谱和，例如在有限温度振荡器中发生的那些。
Using a regularization by putting the system in finite volume, we develop a novel approach to form factor perturbation theory for non-integrable models described as perturbations of integrable ones. This permits to go beyond first order in form factor perturbation theory and in principle works to any order. The procedure is carried out in detail for double sine-Gordon theory, where the vacuum energy density and breather mass correction is evaluated at second order. The results agree with those obtained from the truncated conformal space approach. The regularization procedure can also be used to compute other spectral sums involving disconnected pieces of form factors such as those that occur e.g. in finite temperature correlators.