スピン系の相転移・臨界現象
,非平衡定常系の熱力学の構築
,量子統計力学の基礎づけ
,強相関電子系における強磁性の起源
,量子多体系
,数理物理学
,phase transition and critical phenomena in spin systems
,construction of thermodynamics for nonequilibrium steady state
,foundation of quantum statistical mechanics
,origin of ferromagnetism in strongly interacting electron systems
,quantum many-body systems
,mathematical physics
We develop a controlled high-temperature expansion for nonequilibrium steady states of the driven lattice gas, the "Ising model" for nonequilibrium physics. We represent the steady state as P(eta)proportional to e(-beta H(eta)-Psi(eta)) and evalua...
We develop a controlled high-temperature expansion for nonequilibrium steady states of the driven lattice gas, the "Ising model" for nonequilibrium physics. We represent the steady state as P(eta)proportional to e(-beta H(eta)-Psi(eta)) and evalua...
COMMUNICATIONS IN MATHEMATICAL PHYSICS 242(3) 445-472 2003年11月
It is believed that strong ferromagnetic orders in some solids are generated by subtle interplay between quantum many-body effects and spin-independent Coulomb interactions between electrons. Here we describe our rigorous and constructive approach...
JOURNAL OF PHYSICS-CONDENSED MATTER 10(20) 4353-4378 1998年5月
The Hubbard model is a 'highly oversimplified model' for electrons in a solid which interact with each other through extremely short-ranged repulsive (CouIomb) interaction. The Hamiltonian of the Hubbard model consists of two parts: H-hop which de...