activity
20242026
collaborators

8 papers

cond-mat.dis-nn2026

Absence of Spin-Glass Order on Migdal--Kadanoff Hierarchical Lattices near Three Dimensions

Manaka Okuyama, Masayuki Ohzeki

We derive a rigorous sufficient condition for the absence of spin-glass order in the Ising spin glass with symmetric binary couplings on Migdal--Kadanoff (MK) hierarchical lattices…

math-ph2026

Griffiths inequalities and Gibbs-Bogoliubov inequality for general gauge glasses with Gaussian disorder on Nishimori line

Manaka Okuyama, Masayuki Ohzeki

We consider a class of gauge glass models with Gaussian disorder on the Nishimori line, including the Ising spin glass, the gauge glass, the gauge glass, and the gauge-i…

math-ph2026

Existence of a Phase Transition in the One-Dimensional Ising Spin Glass Model with Long-Range Interactions on the Nishimori Line

Manaka Okuyama, Masayuki Ohzeki

Dyson [Commun. Math. Phys. 12, 91 (1969)] rigorously proved the existence of a phase transition in the one-dimensional Ising model with long-range interactions of the form

cond-mat.dis-nn2025

Temperature chaos as a logical consequence of the reentrant transition in spin glasses

Hidetoshi Nishimori, Masayuki Ohzeki, Manaka Okuyama

Temperature chaos is a striking phenomenon in spin glasses, where even slight changes in temperature lead to a complete reconfiguration of the spin state. Another intriguing effect…

cond-mat.dis-nn2025

Free energy equivalence between mean-field models and nonsparsely diluted mean-field models

Manaka Okuyama, Masayuki Ohzeki

We studied nonsparsely diluted mean-field models that differ from sparsely diluted mean-field models, such as the Viana--Bray model. When the existence probability of each edge fol…

math-ph2025

Existence of long-range order in random-field Ising model on Dyson hierarchical lattice

Manaka Okuyama, Masayuki Ohzeki

We study the random-field Ising model on a Dyson hierarchical lattice, where the interactions decay in a power-law-like form, , with respect to the distance. With…