Representations are special functions on groups that give us a way to study abstract groups using matrices, which are often easier to understand. In particular, we are often interested in irreducible representations, which can be thought of as the building blocks of all representations. Much of the information about these representations can then be understood by instead looking at the trace of the matrices, which we call the character of the representation. This paper will address restricting characters to subgroups by shrinking the domain of the original representation to just the subgroup. In particular, we will discuss the problem of determining when such restricted characters remain irreducible for certain low-rank classical groups.
"Irreducible character restrictions to maximal subgroups of low-rank classical groups of types $B$ and $C$." Involve 12 (4) 607 - 631, 2019. https://doi.org/10.2140/involve.2019.12.607