Discontinuities

PathIntegralLinear is a path integral along a linear path

\[\phi (\tau; q^-, q^+) = (1-\tau) q^- + \tau q^+ .\]

PathIntegralTrigonometric is a path integral along a cos^2/sin^2 path

\[\phi (\tau; q^-, q^+) = \cos^2 (\pi \tau / 2) q^- + \sin^2 (\pi \tau / 2) q^+ .\]