In mathematics, particularly matrix theory, a Stieltjes matrix, named after Thomas Joannes Stieltjes, is a real  symmetric positive definite matrix with nonpositive off-diagonal entries.
In the field of mathematics and specifically within matrix theory, a Stieltjes matrix, honoring Thomas Joannes Stieltjes, refers to a real symmetric positive definite matrix featuring only nonpositive values in its off-diagonal positions.