Dobado González, AntonioSantalla Arribas, Silvia Noemí2023-06-202023-06-202002-05-010556-282110.1103/PhysRevD.65.096011https://hdl.handle.net/20.500.14352/58654©The American Physical Society. The authors want to thank A. Gomez Nicola and J. R. Pelaez for reading the manuscript. This work has been partially supported by the Ministerio de Educación y Ciencia (Spain) (CICYT AEN 97-1693 and PB98-0782).By using chiral perturbation theory and the Uehling-Uhlenbeck equation we compute the viscosity of a pion gas, in the low temperature and low density regime, in terms of the temperature and the pion fugacity. The viscosity turns out to be proportional to the square root of the temperature over the pion mass. Next to leading corrections are proportional to the temperature over the pion mass to 3/2.engjournal articlehttp://prd.aps.org/abstract/PRD/v65/i9/e096011http://prd.aps.orgopen access53Astronomy & AstrophysicsPhysicsParticles & FieldsFísica (Física)22 Física