collaborators

5 papers

math.OC2026

Radial-type error bounds for semidefinite feasibility problems without strict feasibility: qualitative estimates and asymptotic tightness

Mitsuhiro Nishijima, Guoyin Li, Bruno F. Lourenço

In this paper, we develop a systematic framework for deriving explicit error bounds for semidefinite feasibility problems without assuming strict feasibility (Slater's condition),…

math.OC2026

Copositive and completely positive cones over symmetric cones of rank at least 5

Mitsuhiro Nishijima

We study copositive and completely positive cones over symmetric cones of rank at least , with particular emphasis on whether these cones are spectrahedral shadows and on the be…

math.OC2026

Inexact subgradient algorithm with a non-asymptotic convergence guarantee for copositive programming problems

Mitsuhiro Nishijima, Pierre-Louis Poirion, Akiko Takeda

In this paper, we propose a subgradient algorithm with a non-asymptotic convergence guarantee to solve copositive programming problems. The subproblem to be solved at each iteratio…

math.OC2026

Facial structure of copositive and completely positive cones over a second-order cone

Mitsuhiro Nishijima, Bruno F. Lourenço

We classify the faces of copositive and completely positive cones over a second-order cone and investigate their dimension and exposedness properties. Then we compute two parameter…

math.OC2024

Non-facial exposedness of copositive cones over symmetric cones

Mitsuhiro Nishijima, Bruno F. Lourenço

In this paper, we consider copositive cones over symmetric cones and show that they are never facially exposed when the underlying cone has dimension at least 2. We do so by explic…