Itaru Sasaki

Ground state of the massless Nelson model in a non-Fock representation

We consider a model of a particle coupled to a massless scalar field (the massless Nelson model) in a non-Fock representation. We prove the existence of a ground state of the system, applying the method of Griesemer, Lieb, and Loss.

Ground state energy of the polaron in the relativistic quantum electrodynamics

We consider the polaron model in the relativistic quantum electrodynamics( QED). We prove that the ground state energy of the model is finite for all values of the fine-structure constant and the ultraviolet cutoff

Spectral Analysis of the Dirac Polaron

\Lambda

Boltzmann Limit and Quasifreeness for a Homogenous Fermi Gas in a Weakly Disordered Random Medium

. Moreover we give an upper bound and a lower bound of the ground state energy.

Spectral properties of a Dirac operator in the chiral quark soliton model

A system of a Dirac particle interacting with the radiation field is considered. The Hamiltonian of the system is defined by

A mathematical analysis of dressed photon in ground state of generalized quantum Rabi model using pair theory

H = \alpha\cdot(\hat\mathbf{p}-q\mathbf{A}(\hat\mathbf{x}))+m\beta + H_f

Enhanced binding of an N-particle system interacting with a scalar field II. Relativistic version

where

Measure theoretical approach to recurrent properties for quantum dynamics

q\in\mathbb{R}

Note on the spectrum of discrete Schrödinger operators

is a coupling constant,

Ground State of a Model in Relativistic Quantum Electrodynamics with a Fixed Total Momentum

\mathbf{A}(\hat\mathbf{x})