One of the most important problems in physics is understanding the emergent properties of systems made up of large numbers of interacting particles, also known as many-body systems. From a microscopic point of view, all types of matter can be modeled through a many-body quantum Hamiltonian that encompasses all the fundamental interactions between their constituent particles. Of great importance are the systems formed by electrons in which the correlation between them makes it possible to explain phenomena such as superconductivity, the Kondo effect, charge density waves and spin density waves. Nowadays, a great variety of low-dimensional unconventional superconductors are known in which the spatial wave functions of the pairs of electrons present symmetries other than spherical.

The IFUNAM addresses the study of new models, beyond of BCS theory, which allow us to understand the mechanism of formation of these pairs. For this, different methodologies are used to solve, in an approximate way, the problem of electronic correlation from simple models.