7 papers
A construction of 2-arc-transitive non-solvable covers of complete graphs
Jiyong Chen, Cai Heng Li, Ci Xuan Wu +1
We construct connected -arc-transitive covers of complete graphs with non-abelian characteristically simple transformation groups. This solves the existence problem for non-solv…
Proportion of chiral maps with automorphism group and
Jiyong Chen, Yi Xiao Tang
Orientably-regular maps are highly symmetric embeddings of graphs in oriented surfaces. Among them, chiral maps are those which fail to be isomorphic to their mirror images. We pro…
On the Codegree graphs of finite groups
Jiyong Chen, Ni Du, Leyi Li
The codegree of an irreducible character of a finite group is defined as . The codegree graph of a finite group is the graph whose vertices are t…
On Bi-rotary Maps of Negative Prime Power Euler Characteristic
Jiyong Chen, Zhaochen Ding, Cai Heng Li
A map is bi-orientable if it admits an assignment of local orientations to its vertices such that for every edge, the local orientations at its two endpoints are opposite. Such an…
Elusive groups from non-split extensions
Jiyong Chen, Melissa Lee, Dorde Mitrovic +2
A finite transitive permutation group is elusive if it contains no derangements of prime order. These groups are closely related to a longstanding open problem in algebraic graph t…
Non-solvable -arc-transitive covers of Petersen graphs
Jiyong Chen, Cai Heng Li, Ci Xuan Wu +1
We construct connected -arc-transitive covers of the Petersen graph with non-solvable transformation groups, solving the long-standing problem for the existence of such covers.
Coverings of Groups, Regular Dessins, and Surfaces
Jiyong Chen, Wenwen Fan, Cai Heng Li +1
A coset geometry representation of regular dessins is established, and employed to describe quotients and coverings of regular dessins and surfaces. A characterization is then give…