a^2/b, where a and b are both CVX (optimization) variables, is non-convex. Why isn't CVX accepting my model? READ THIS FIRST!
You haven’t shown us enough details of your problem for us to determine whether there may be a reformulation into a form acceptable by CVX. So for now, we will presume that the problem is not convex.
Edit: Ignore my post, except for the link. Go by ncg’s post below.