11 papers
Forced Coincidence and Its Boundary in Finite Condition Structures
Daisuke Hirota
Accounts of organizational dissolution explain survivor homogenization, temporally concentrated exit, and fragmentation into cohesive subgroups in different vocabularies. Their rec…
On the Fischer-Muszély equation for the positive cones of -algebras
Daisuke Hirota, Jyamira Oppekepenguin
We study the Fischer-Muszély functional equation for the positive semidefinite and the positive definite cones of unital -algebras. We show that any bijection between the posi…
Surjective isometries on the positive parts of the unit spheres of some function spaces
Yuta Enami, Daisuke Hirota, Hironao Koshimizu +1
We consider the space of continuously differentiable functions on the closed unit interval and the space of Lipschitz continuous fun…
Globalization of local sign structures for phase-isometries on uniform algebras
Yuta Enami, Daisuke Hirota, Izuho Matsuzaki +1
We study surjective phase-isometries between the unit spheres of uniform algebras. Although such maps preserve maximal convex sets up to signs, the resulting local sign ambiguity p…
The Impossibility of Cohesion Without Fragmentation
Daisuke Hirota
Accounts of social division and cohesion presuppose relations whose maintenance already depends on positional compatibility. We develop this feasibility layer as a static theory: a…
Norm additive mappings between commutative -algebras in the range
Daisuke Hirota
Let \( A_i \) be a commutative \( C^{*} \)-algebra for \( i = 1, 2 \), and denote by \( A_i^{+} \) its positive cone, consisting of all positive elements of \( A_i \). In this pape…
Rational Adversaries and the Maintenance of Fragility: A Game-Theoretic Theory of Rational Stagnation
Daisuke Hirota
Cooperative systems often remain in persistently suboptimal yet stable states. This paper explains such "rational stagnation" as an equilibrium sustained by a rational adversary wh…
Phase-isometries between the positive cones of the Banach space of continuous real-valued functions
Daisuke Hirota, Izuho Matsuzaki, Takeshi Miura
For a locally compact Hausdorff space , we denote by the Banach space of all continuous real-valued functions on vanishing at infinity equipped with the…
Every commutative JB-triple satisfies the complex Mazur--Ulam property
David Cabezas, María Cueto-Avellaneda, Daisuke Hirota +2
We prove that every commutative JB-triple satisfies the complex Mazur--Ulam property. Thanks to the representation theory, we can identify commutative JB-triples as spaces…
Exploring new solutions to Tingley's problem for function algebras
María Cueto-Avellaneda, Daisuke Hirota, Takeshi Miura +1
In this note we present two new positive answers to Tingley's problem in certain subspaces of function algebras. In the first result we prove that every surjective isometry between…
Surjective isometries between unitary sets of unital JB-algebras
María Cueto-Avellaneda, Yuta Enami, Daisuke Hirota +2
This paper is, in a first stage, devoted to establish a topological--algebraic characterization of the principal component, , of the set of unitary elements, $\m…