We present an alternative approach to justify the electric charge quantization by means of non-global electromagnetic potentials. We adopt a non-global potential whose singularity does not goes over to infinity and can be entirely embedded into an arbitrarily small closed ball.

First of all, I would like to express my gratitude to professor Elcio Abdalla for giving me the opportunity to work under his supervision as well as the freedom to follow any research direction I wished. I am equally grateful to Bertha Cuadros-Melgar for her constant support over all these years, the fruitful collaborations, and for each of her countless objections on the random use of commas in my english writing. I am grateful also to Jorge Noronha for nice discussions, Fernando Brandt for valuable comments on the text, and in particular Diego Trancanelli for comments, discussions and his tremendous support in my struggle to find a postdoc position. I also want to thank everyone at USP that contributed to make this 4-year journey so enjoyable. Specially Marcela Muniz and Lucas Müssnich (honorable mention here to Ana Luiza for her nice occasional stays), with whom sharing the 337 office has always been a privilege-and that's not because of the espresso machine or the sofa. Also