5 papers
Structural Oscillatority Criterion of Boolean Networks
Hiroki Kodama
Azuma et al. showed that a cactus-expandable Boolean network is structurally oscillatory if all the simple cycles of contain an odd number of inhibiting edges. We show th…
Characterization of cactus-expandable digraphs via doubly bidirectionally connected pairs
Hiroki Kodama
Azuma et al.\ showed that a strongly connected digraph without a doubly bidirectionally connected pair is cactus-expandable. We prove the converse: if a digraph has a doubly bidire…
Distinguishing regular polygons, cycle graphs, and circular metric spaces by the distance multiset and magnitude
Hiroki Kodama, Jun O'Hara
We investigate how effectively finite metric spaces can be distinguished by distance-based invariants. As model spaces, we consider regular polygons, cycle graphs, and their genera…
Lefschetz fibrations on the Milnor fibers of cusp and simple elliptic singularities
Naohiko Kasuya, Hiroki Kodama, Yoshihiko Mitsumatsu +1
We show that the total space of the Milnor fibration associated with any cusp or simple elliptic singularity in complex three variables admits an -parametric genus-one Lefsche…
Relative simplicity of the universal coverings of transformation groups and Tsuboi's metric
Morimichi Kawasaki, Mitsuaki Kimura, Hiroki Kodama +3
Many transformation groups on manifolds are simple, but their universal coverings are not. In the present paper, we study the concept of relatively simple group, that is, a group w…