We prove positivity results about linearization and connection coefficients for Bessel polynomials. The proof is based on a recursion formula and explicit formulas for the coefficients in special cases. The result implies that the distribution of a convex combination of independent Studentt random variables with arbitrary odd degrees of freedom has a density which is a convex combination of cer...

In this paper, we write down the separable Werner state in a two-qubit system as a convex combination of product states explicitly. The Werner state in a two-qubit system has a single real parameter and varies from inseparable state to separable state according to the value of its parameter. The convex combination of product states gives a hidden variable model to the separable Werner state.

We prove positivity results about linearization and connection coefficients for Bessel polynomials. The proof is based on a recursion formula and explicit formulas for the coefficients in special cases. The result implies that the distribution of a convex combination of independent Studentt random variables with arbitrary odd degrees of freedom has a density which is a convex combination of cer...

Gottschalk and Vygen proved that every solution of the well-known subtour elimination linear program for traveling salesman paths is a convex combination of a set of more and more restrictive “generalized Gao trees” of the underlying graph. In this paper we give a short proof of this, as a layered convex combination of bases of a sequence of more and more restrictive matroids. Our proof implies...

It has been suggested that the \Maximum Realisable Receiver Operating Characteristics" for a combination of classiiers is the convex hull of their individual ROCs Scott et al., 1998]. As expected in at least some cases better ROCs can be produced. We show genetic programming (GP) can automatically produce a combination of classi-ers whose ROC is better than the convex hull of the supplied class...