From [Isaacs et.al. 2005][1] > Conjecture C. Let χ be a primitive > irreducible character of an arbitrary > finite group G. Then χ(1) divides | > clG(g)| for some element g ∈ G. > > Here, of course, we have written > clG(g) to denote the class of g in G. > We have checked that Conjecture C > holds for all irreducible characters > (primitive or not) of all groups in > the Atlas [1]. **Question 1** What is motivation for this ? Is it possible to describe what are conjugacy class(es) should correspond to irreducible representation in this way ? **Question 2** Is it still open ? ------------- The authors write: > We now digress to explain our original > motivation for considering these > questions. There are numerous > parallels and analogies between > theorems concerning the of set > irreducible character degrees of a > finite group and theorems concerning > the set of conjugacy class sizes of > such groups. This suggests that > perhaps there are some subtle > arithmetic connections between these > two sets of integers associated with a > given group. One such connection that > is easy to see is that each prime > number that divides an irreducible > character degree of G must also divide > some class size of G. If G is > solvable, then S. Dolfi showed that > more is true. He proved [2] that given > any two distinct primes p and q such > that pq divides some irreducible > character degree of a solvable group > G, then pq also divides some class > size of G. One might conjecture that > the analogous assertion for three or > more distinct primes is also true, but > as far as we know, this remains open. [1]: http://www.uv.es/amoquin/35.pdf