10 citations · 19 across the 19 of their papers we have counts for
20 papers
Representation Theory of Canonical Commutation Relations Arising from the Quantization of the Klein-Gordon Equation with an External Potential
Yasumichi Matsuzawa, Itaru Sasaki, Akito Suzuki
We investigate the Weyl representation of the canonical commutation relations for a model describing a quantized massive scalar field under the influence of an external potential.…
Classification of abstract Bose field models
Yasumichi Matsuzawa
We classify a class of abstract Bose field models in quantum field theory up to unitary equivalence. The class includes abstract free Bose field models, abstract van Hove--Miyatake…
Holomorphy of the ground state and energy for bosonic quadratic Hamiltonians
Kota Imura, Shinnosuke Izumi, Yasumichi Matsuzawa +1
We study the holomorphy of the ground state and its energy with respect to the coupling constant for bosonic quadratic Hamiltonians. We prove general theorems establishing this hol…
A direct derivation of an effective Hamiltonian in non-relativistic quantum electrodynamics
Yasumichi Matsuzawa
We present a direct derivation of Arai's effective Hamiltonian in non-relativistic quantum electrodynamics without relying on the scaling limit. Our result applies to a broader cla…
Index Theorems for One-dimensional Chirally Symmetric Quantum Walks with Asymptotically Periodic Parameters
Yasumichi Matsuzawa, Yohei Tanaka, Kazuyuki Wada
We focus on index theory for chirally symmetric discrete-time quantum walks on the one-dimensional integer lattice. Such a discrete-time quantum walk model can be characterised as…
The Witten index for one-dimensional split-step quantum walks under the non-Fredholm condition
Yasumichi Matsuzawa, Akito Suzuki, Yohei Tanaka +2
It is recently shown that a split-step quantum walk possesses a chiral symmetry, and that a certain well-defined index can be naturally assigned to it. The index is a well-defined…