Main . Non-reciprocal active matter consists of local, non-reciprocal and non-conservative interactions15 , 16 , 17. It is described by odd, namely asymmetric, or non-Hermitian matrices and tensors. Such materials exist across a wide range of scales, from electron transport19 , 20 , 21 , 32 , 33 , 34, electronics35, optomechanics36and photonics22 , 37to colloids38, driven emulsions39, biophysics40, mechanics5 , 7 , 41...