What are the conditions for a binary matrix $A$ (matrix with elements 0 or 1) to be positive definite (not even symmetric), i.e.
$\forall x\neq 0, x^TAx>0, A_{ij}\in \{0,1 \}$
Put it another way, what adjacency matrices are positive definite?
What are the conditions for a binary matrix $A$ (matrix with elements 0 or 1) to be positive definite (not even symmetric), i.e.
$\forall x\neq 0, x^TAx>0, A_{ij}\in \{0,1 \}$
Put it another way, what adjacency matrices are positive definite?