Kenji Toyonaga. The effect of removing a 2-downer edge or a cut 2-downer edge triangle for an eigenvalue. Special Matrices. 2023. 11, spma-2022-0186
Kenji Toyonaga, Charles R. Johnson. Parter Vertices and Generalization of the Downer Branch Mechanism in the General Setting. Linear and Multilinear Algebra. 2023
Kenji Toyonaga, Charles R. Johnson. The Effect of Perturbation of an Off-diagonal Entry Pair on the Geometric Multiplicity of an Eigenvalue. Linear algebra and its applications. 2021. 615. 112-142
Charles R. Johnson, Carlos M. Saiago, Kenji Toyonaga. Change in vertex status after removal of another vertex in the general setting. Linear algebra and its applications. 2021. 612. 128-145