6 papers
Asymptotics of Ground States for Helium-Like and Bosonic Atoms in a Two-Cluster Region
Yukimi Goto
We study the asymptotic behavior of positive ground states of -particle atomic Coulomb Hamiltonians in a two-cluster region. For the -particle ground state , its one-parti…
Superconductivity and Low Energy Excitations in an Attractive Hubbard Model
Yukimi Goto, Tohru Koma, Hironobu Yoshida
We study an attractive Hubbard model on bipartite lattices. In the grand canonical formalism,we prove the existence of superconducting long-range order in the ground state on Lieb…
Antiferromagnetic Long-Range Order in a Lattice Fermion Model
Yukimi Goto, Tohru Koma
We study a lattice fermion model with antiferromagnetic interactions on the three-dimensional cubic lattice. The hopping term of the Hamiltonian has a Weyl-type dispersion. We prov…
Violation of Parity and Flavor Symmetries in a Nambu-Jona-Lasinio Model
Yukimi Goto, Tohru Koma
We study a lattice Nambu-Jona-Lasinio model with certain continuous chiral and two-flavor symmetries. For the Hamiltonian of the model, we construct a ground state which breaks the…
Absence of ground states for anions
Yukimi Goto
We show that the -electron Hamiltonian with the total nuclear charge has no normalizable ground state if the ground state energy satisfies $E(N, Z)= E(N-…
Nambu-Goldstone modes in a lattice Nambu-Jona-Lasinio model with multi flavor symmetries
Yukimi Goto, Tohru Koma
We study a lattice Nambu-Jona-Lasinio model with SU(2) and SU(3) flavor symmetries of staggered fermions in the Kogut-Susskind Hamiltonian formalism. This type of four-fermion inte…