Carlos Gustavo Tamm de Araújo Moreira is a Brazilian mathematician working on dynamical systems, ergodic theory, number theory and combinatorics. Moreira is currently a researcher at the Instituto Nacional de Matemática Pura e Aplicada (IMPA), where he goes by the nickname "Gugu". He is also a member of the Brazilian Mathematical Olympiad Commission, a fanatic fan of the Brazilian football team Flamengo and a member of the Brazilian Communist Party (PCB).