We investigate the completely positive semidefinite cone CS+, a new matrix cone consisting of all n×n matrices that admit a Gram representation by positive semidefinite matrices (of any size). In particular, we study relationships between this cone and the completely positive and the doubly nonnegative cone, and between its dual cone and trace positive non-commutative polynomials. We use this n...

• unify, and generalize seemingly disparate, classical sufficient conditions: polyhedrality of the cone, and “Slater” type conditions; • are necessary and sufficient, when the dual cone belongs to a class, that we call nice cones. Nice cones subsume all cones amenable to treatment by efficient optimization algorithms: for instance, polyhedral, semidefinite, and p-cones. • provide similarly attr...

A molecular basket was obtained by linking four cholate units to a cone-shaped calix[4]arene scaffold through azobenzene spacers. The molecule turns its polar faces inward in nonpolar solvents to bind polar molecules such as sugar derivatives. In polar solvents, the nonpolar faces turn inward, allowing the binding of hydrophobic guests such as pyrene. The molecule can also respond to UV irradia...

The characteristics of the high-energy emission from polar cap accelerators will be discussed. Particles accelerated in the “slot gap” near the polar cap rim will reach altitudes of several stellar radii before initiating pair cascades, producing a wide hollow cone of emission in young pulsars and some millisecond pulsars. Model X-ray and gamma-ray spectra and pulse profiles, based on Monte-Car...

This paper deals with optimality conditions to solve nonlinear programming problems. The classical Karush-Kuhn-Tucker (KKT) optimality conditions are demonstrated through a cone approach, using the well known Farkas’ Lemma. These conditions are valid at a minimizer of a nonlinear programming problem if a constraint qualification is satisfied. First we prove the KKT theorem supposing the equalit...

Efficient points are obtained for cone-ordered maximizations in n R using the method of scalarization. Various scalarizations are presented for ordering cones in general and then for the important special case of polyhedral cones. For polyhedral cones, it is shown how to find vectors in the positive dual cone that are needed for a scalarized objective function. Instructive examples are presented.

For a proper cone K ⊂ R and its dual cone K∗ the complementary slackness condition x s = 0 defines an n-dimensional manifold C(K) in the space { (x, s) | x ∈ K, s ∈ K∗ }. When K is a symmetric cone, this fact translates to a set of n bilinear optimality conditions satisfied by every (x, s) ∈ C(K). This proves to be very useful when optimizing over such cones, therefore it is natural to look for...

Let Ln be the n-dimensional second order cone. A linear map from Rm to Rn is called positive if the image of Lm under this map is contained in Ln. For any pair (n,m) of dimensions, the set of positive maps forms a convex cone. We construct a linear matrix inequality (LMI) that describes this cone. Namely, we show that its dual cone, the cone of Lorentz-Lorentz separable elements, is a section o...

In [Bat92] Batyrev studied the cone of pseudo-effective divisors on Q-factorial terminal threefolds and its dual cone, the cone of nef curves. Given a uniruled Q-factorial terminal threefold X , and an ample divisor H on X , he showed that the effective threshold of H (see Definition 1.5 below) is a rational number. Using similar arguments, Fujita generalized this result to log terminal pairs (...

The closure of the convex cone generated by all flag f -vectors of graded posets is shown to be polyhedral. In particular, we give the facet inequalities to the polar cone of all nonnegative chain-enumeration functionals on this class of posets. These are in one-to-one correspondence with antichains of intervals on the set of ranks and thus are counted by Catalan numbers. Furthermore, we prove ...