Articles in this volume are based on presentations given at the IV Meeting of Mexican Mathematicians Abroad (IV Reunion de Matematicos Mexicanos en el Mundo), held from June 10-15, 2018, at Casa Matematica Oaxaca (CMO), Mexico. This meeting was the fourth in a series of ongoing biannual meetings bringing together Mexican mathematicians working abroad with their peers in Mexico. This book features surveys and research articles from five broad research areas: algebra, analysis, combinatorics, geometry, and topology. Their topics range from general relativity and mathematical physics to...