In systems with a moderate sign problem, such as field theories at a sufficiently high temperature or in a sufficiently small volume, the sign problem is not too severe and useful results can be obtained by various methods, such as more carefully tuned reweighting, analytic continuation from imaginary μ {\displaystyle \mu } to real μ {\displaystyle \mu } , or Taylor expansion in powers of μ {\displaystyle \mu } .[1][9]