A “class group” obstruction for the equation
In this paper, we study equations of the form , where is a binary form, homogeneous of degree , which is supposed to be primitive and irreducible, and is any fixed integer. Using classical tools in algebraic number theory, we prove that the existence of a proper solution for this equation implies the existence of an integral ideal of given norm in some order in a number field, and also the existence of a specific relation in the class group involving this ideal. In some cases, this result...