Biconvex optimization

Biconvex optimization refers to a class of optimization problems that involve a biconvex function. A function \( f(x, y) \) defined on a product space \( X \times Y \) (where \( X \) and \( Y \) are convex sets) is considered biconvex if it is convex in \( x \) for each fixed \( y \), and convex in \( y \) for each fixed \( x \).