Preface

Abstract

Preface The Meeting of Physics is an event initiated by a group of Peruvian scientists, some of whom work abroad. It aims to motivate and promote physics in Peru, presenting the scientific contributions of researchers and students from different Peruvian universities and scientific organizations. This event is also a great opportunity to meet and initiate or continue scientific collaborations with local and international guests some of these are renowned scientists.Unfortunately, during 2020 and 2021 the global pandemic that affected us all also drastically slowed research activities. Despite all these, we managed to continue organizing our Meetings of Physics using online technologies. It took a while for researchers and students to complete their articles for the proceedings and for us to get the corresponding funding, but finally these Joined Proceedings of the XIX and XX Meetings of Physics were produced.In these Proceedings we present a selection of works that were exhibited in the plenary and parallel lectures, as well as in online “poster” sessions.The editors wish to thank the Faculty of Sciences of the National University of Engineering (UNI) in Lima, Peru, and all those who made it possible the XIX and XX Meetings of Physics.The editorial Committee:Carmen Eyzaguirre (UNI, Peru)Ener Salinas (Hitachi Energy Research, Sweden)Rosendo Ochoa (UNI, Peru)Javier Solano (UNMSM, Peru)