Showing papers by "Harald Grosse published in 1989"
TL;DR: In this article, the authors show that the spectrum of the Hubbard model shows permanent degeneracy of levels with different symmetries, if one considers only symmetry operators independent of the coupling constant.
Abstract: The spectrum of the Hubbard model shows permanent degeneracy of levels with different symmetries, if one considers only symmetry operators independent of the coupling constant. This suggests the existence of symmetry operators which depend on the coupling constant. We find these highly nontrivial operators and show that they explain the degeneracies in the energy spectrum.
29 citations