On analytic formulas of Feynman propagators in position space

We correct an inaccurate result of previous work on the Feynman propagator in position space of a free Dirac field in （3 ＋ 1）-dimensional spacetime; we derive the generalized analytic formulas of both the scalar Feynman propagator and the spinor Feynman propagator in position space in arbitrary （D ＋ 1）- dimensional spacetime; and we further find a recurrence relation among the spinor Feynman propagator in （D＋1）-dimensional spacetime and the scalar Feynman propagators in （D＋1）-, （D-1）- and （D＋3）-dimensional spacetimes.