Wick rotation
formal analytic continuation of the time coordinate that changes a Lorentzian metric signature to a Euclidean one
en-US/ˈwɪk ɹoʊˈteɪʃən/
en-GB/wɪk ɹəʊˈteɪʃən/
formal analytic continuation of the time coordinate that changes a Lorentzian metric signature to a Euclidean one