We derive an explicit expression for the leading term in the long-time, large-distance asymptotic expansion of a transverse dynamical two-point function of the XX chain in the spacelike regime. This expression is valid for all nonzero finite temperatures and for all magnetic fields below the saturation threshold. It is obtained here by means of a straightforward term-by-term analysis of a thermal form factor series, derived in previous work, and demonstrates the usefulness of the latter.

中文翻译：

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类空间状态下XX链横向相关函数的长时间大距离渐近

我们推导出了类空间状态下 XX 链的横向动力学两点函数的长期、大距离渐近展开的首项的显式表达式。该表达式适用于所有非零有限温度和低于饱和阈值的所有磁场。它是通过对先前工作中导出的热形状因子系列的直接逐项分析获得的，并证明了后者的有用性。