University of Isfahan Transactions on Combinatorics 2251-8657 8 1 2019 03 01 On problems concerning fixed-point-free permutations and on the polycirculant conjecture-a survey 15 40 23166 10.22108/toc.2018.112665.1585 EN Majid Arezoomand University of Larestan Alireza Abdollahi University of Isfahan Pablo Spiga Dipartimento di Matematica e Applicazioni, University of Milano-Bicocca, Journal Article 2018 08 25 Fixed-point-free permutations‎, ‎also known as derangements‎, ‎have been studied for centuries‎. ‎In particular‎, ‎depending on their applications‎, ‎derangements of prime-power order and of prime order have always played a crucial role in a variety of different branches of mathematics‎: ‎from number theory to algebraic graph theory‎. ‎Substantial progress has been made on the study of derangements‎, ‎many long-standing open problems have been solved‎, ‎and many new research problems have arisen‎. ‎The results obtained and the methods developed in this area have also effectively been used to solve other problems regarding finite vertex-transitive graphs‎. ‎The methods used in this area range from deep group theory‎, ‎including the classification of the finite simple groups‎, ‎to combinatorial techniques‎. ‎This article is devoted to surveying results‎, ‎open problems and methods in this area‎. https://toc.ui.ac.ir/article_23166_1e1c1fe183cadcd86904ba2543084f1f.pdf