We show how to construct a complete set of eigenstates of the hamiltonian of the one-dimensional Hubbard model on a lattice of even length L. This is done by using the nested Bethe Ansatz and the SO(4) symmetry of the model. We discuss in detail how the counting of independent eigenstates is carried out.

Recent developments in the Triple Bottom Line reporting literature suggest a need for standards that ensure consistency, openness, transparency and inclusivity in the Triple Bottom Line reports produced. These standards, it is argued, provide assurances to stakeholders about the quality of a Triple Bottom Line report, and should lead to more inclusive business-stakeholder relations. The link be...

Using the negative U Hubbard model we analyze normal state properties of a superconductor. In this model there exists a characteristic pairing temperature TP above a superconducting critical temperature. Below TP electrons start to form incoherent pairs. The fluctuations in charge and phase are precursors of charge density wave and superconductivity phases depending on band filling. They lead n...