Una introducción a los teoremas de punto fijo y a la existencia de equilibrios en economía

The following document describes what constitutes fixed point theorems and how they fit into some notions of equilibrium in economics. The first section defines fixed points for functions and for correspondence, particularly the Brouwer's and Kakutani's fixed point theorems and what is an equilibrium; the second reviews the walrasian equilibrium and the Nash equilibrium, showing the relevance of the fixed point theorems to prove its existence. Concluding remarks realize that modeling techniques have spread almost on par with new assumptions in the profession, which revolutionized the way we study economics.