A simple solution to the Braga-Mello conjecture
  Recently Braga and Mello conjectured that for a given natural number n there is a piecewise linear system with two zones in the plane with exactly n limit cycles. In this paper we prove a result from which the conjecture is an immediate consequence. Several explicit examples are given where location and stability of limit cycles are provided. 
Douglas Duarte Novaes, Enrique Ponce
math.DS