2019-10-22T05:53:55Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/690602018-10-09T00:47:25Zhdl_2115_45007hdl_2115_116On the Existence and Uniqueness of Ground States of the Spin-Boson HamiltonianArai, A.Hirokawa, M.open access410The existence and uniqueness of ground states of the spin-boson Hamiltonian HsB are considered. The main results in the case of massive bosons include: (i)(existence) there exists a ground state without restriction for the strength of the coupling constant ; (ii)(uniqueness) under a mild (nonperturbative) condition for the parameters contained in HsB, HsB has only one ground state; (iii) (degeneracy) under a certain condition for the parameters of HsB which is weaker than that of (ii), the number of the ground states is at most two. In the case of massless bosons, the existence of a ground state of H SB is shown as a limit of ground states of the massive case. The methods used are nonperturbative.1995-09-01engdepartmental bulletin paperVoRhttps://doi.org/10.14943/83456http://hdl.handle.net/2115/6906010.14943/83456Hokkaido University Preprint Series in Mathematics309220https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/69060/1/pre309.pdfapplication/pdf834.64 KB1995-09-01