Hi,

as in the figure,

I have a vector \bm{x} and \bm{y}, and a constraint in (3) as the sum of element-wise cubic over quad, the problem is that I do not know how to express this constraint in an acceptable way in CVX. As shown in (4) and (5) for the element-wise function, with x,y \ge 0, the Hessian is positive definite, so the left hand side of (3), as a sum of convex function, should be convex.

Many many thanks for the kind help.