During July 2015 we had the visit of Prof. Xavier Caicedo. We was generously working with our team and he gave a talk in the CIEM Colloquia series.

__Title__: *“The Lefschetz transfer principle”*

__Abstract__: The so-called *Lefschetz transfer principle* states that algebraic geometry over the complex numbers is the same as that of any other algebraically closed field with null characteristic. Model Theory explains and allows to generalize this heuristic principle, one of the simplest examples of nontrivial interaction between Logic and other areas in Mathematics. We’ll discuss more general transfer principles illustrating the role of Model Theory as a mathematical instrument in Algebra, Analysis and Number Theory.

The talk was given in Spanish.