Firstly, I would like to thank my incredible advisor, Thibaut Vidal, for all the discussions, help and support in the past years and my coadvisor, Anand Subramanian, for helping making it fun to write a paper and becoming a great friend of mine in the process. I would also like to thank the examination committee, Marco Molinaro and Marcus Poggi, for their insightful comments and suggestions.I would like to thank my family, Elizabeth Zerpini, Ian Mecler, Katia Mecler, Rosinha Goldenstein, Nair Zerpini, Edir Semblano and specially my brother, Davi Mecler, who is also a great colleague in the area.My sincere gratitude also goes to my fellow colleagues, specially Rafael