The Hubbard dimer: exact dynamic exchange-correlation kernel, single and double excitations of a strongly correlated problem

Resumen del trabajo presentado al March Meeting of the American Physical Society, celebrado en New Orleans, Louisiana (USA) del 13 al 17 de marzo de 2017.The Hubbard dimer is an exactly solvable model of a strongly correlated problem. We develop here its exact frequency-dependent exchange-correlation kernel. Armed with this, we analyse the behaviour of the single and double excitations of the model as they evolve from the weak correlation regime deep into the strongly-correlated Mott-Hubbard regime.Peer Reviewe