Heat flux in one-dimensional systems

ACKNOWLEDGMENTS L.R. has been partially supported by Ministero dell'Istruzione dell'Universita e della Ricerca (MIUR) Grant “Dipartimenti di Eccellenza 2018–2022”, Project No. E11G 18 000 35 000 1. C.M.M. thanks the Department of Mathematical Sciences of Politecnico di Torino for its hospitality and acknowledges financial support from the Spanish Government Grant No. PGC2018-099944-B-I00 (MCIU/AEI/FEDER, UE). This work started and developed while C.M.M. was a long-term Visiting Professor of Politecnico di Torino.