Jacques Vélu

Jacques Vélu worked on elliptic curves and explicit isogenies. The original Bordeaux seminar archive verifies the name and his 1970–1971 contribution on elliptic curves.^[ref]

Vélu's formulas construct an isogeny from an elliptic curve and a finite kernel subgroup by summing coordinate corrections over the nonidentity kernel points. They turn the abstract quotient by a subgroup into explicit equations for both the map and the quotient curve. The simple short-Weierstrass formulas require characteristic restrictions and do not replace the distinction between geometric kernel points and inseparable degree.^[ref]