Chollet conjecture

Let $A$ be an $n\times n$ positive semidefinite matrix. Then

\[\operatorname{per}(A)^2 \geq \operatorname{per}(A \circ \overline{A}),\]

where $\operatorname{per}(A)$ is the permanent of a matrix $A$, and $\circ$ denotes the Hadamard product.