How to make this problem convex so that it can be solved by semidefinite programming in cvx? Given $A\in\mathbb{C}^{n\times n}$
\begin{array}{ll} \underset{X\in\mathbb{C^{n\times n}}}{\text{maximize}} & \frac{\mathrm{trace}\big((A^*A+I)X\big)}{\mathrm{trace}\big((A+A^*)X\big)}.\\ \text{subject to} & \mathrm{trace}\big((A-A^*)X\big)=0,\\&\mathrm{trace}(X)=1,\\&X\geq0.\end{array}
I have tried to let $\mathrm{trace}\big((A+A^*)X\big)=1/k$, so that I can rewrite above problem as
\begin{array}{ll} \underset{X\in\mathbb{C^{n\times n}}, k\in\mathbb{R}}{\text{maximize}} & k\times\mathrm{trace}\big((A^*A+I)X\big).\\ \text{subject to} & k\times\mathrm{trace}\big((A+A^*)X\big)=1\\&\mathrm{trace}\big((A-A^*)X\big)=0,\\&\mathrm{trace}(X)=1,\\&X\geq0.\end{array}
CVX code from Matlab:
n=length(A);
A1=A'*A+eye(n,n);
A2=0.5*(A+A');
A3=0.5*(A-A');
cvx_begin
variable X(n,n) hermitian
variable k
minimize(-k*trace(A1*X));
subject to
k*trace(A2*X)==1;
trace(A3*X)==0;
trace(X)==1;
X == hermitian_semidefinite(n);
ERROR code:
Error using .* (line 262)
Disciplined convex programming error:
Invalid quadratic form(s): not a square.
Error in * (line 36)
z = feval( oper, x, y );
Error in QCQP_SDR_GM (line 11)
minimize(-k*trace(A1*X));