In mathematics, a stunted projective space is a construction on a projective space of importance in homotopy theory, introduced by James . Part of a conventional projective space is collapsed down to a point. More concretely, in a real projective space, complex projective space or quaternionic projective space KPn, where K stands for the real numbers, complex numbers or quaternions, one can find (in many ways) copies of KPm, where m < n. The corresponding stunted projective space is then KPn,m = KPn/KPm, In later developments spaces KP∞,m and stunted lens spaces have also been used.