Hello,

it is first time I use the software and I would like to know if this problem can be rewritten somehow to be solved with cvx, or otherway it would be awesome if you can indicate me a program to try to get the solution. I get the error message

```
??? Error using ==> maximize at 36
Disciplined convex programming error:
Cannot maximize a(n) convex expression.
Error in ==> semi at 17
maximize(x1^2+x2^2+x3^2)
```

the code is the following

```
cvx_begin sdp
variables x0 x1 x2 x3 y1 y2 y3 y4 y5
x0==1/sqrt(3)
1/3+x1^2+x2^2+x3^2+y1^2+y2^2+y3^2+y4^2+y5^2<=1
x1==-x3
y1==y5
y2==-y4
x0*X0+x1*X1+x2*X2+x3*X3+y1*Y1+y2*Y2+y3*Y3+y4*Y4+y5*Y5>=0
maximize(x1^2+x2^2+x3^2)
cvx_end
```

X0, X1,…X3,Y1,…Y5,Z1…Z7 (in capital letters) are matrices (spherical tensors) I pretend the product with the variables in lowercase to be positive semidefinite a constraint as well as the other equalities/inequalities after the variable statement.