Phys. rev. res. Phys. rev. res. Virus spread versus contact tracing: Two competing contagion processes Reyna-Lara Adriana Soriano-Paños David Universidad de Zaragoza Gómez Sergio Granell Clara Matamalas Joan T. Steinegger Benjamin Arenas Alex Gómez-Gardeñes Jesús Universidad de Zaragoza 2021 research-article