20,644 research outputs found
Matrix models for classical groups and ToeplitzHankel minors with applications to Chern-Simons theory and fermionic models
We study matrix integration over the classical Lie groups
and , using symmetric function theory and the equivalent formulation
in terms of determinants and minors of ToeplitzHankel matrices. We
establish a number of factorizations and expansions for such integrals, also
with insertions of irreducible characters. As a specific example, we compute
both at finite and large the partition functions, Wilson loops and Hopf
links of Chern-Simons theory on with the aforementioned symmetry
groups. The identities found for the general models translate in this context
to relations between observables of the theory. Finally, we use character
expansions to evaluate averages in random matrix ensembles of Chern-Simons
type, describing the spectra of solvable fermionic models with matrix degrees
of freedom.Comment: 32 pages, v2: Several improvements, including a Conclusions and
Outlook section, added. 36 page
On a conjecture of Gluck
Let and respectively denote the Fitting subgroup and the
largest degree of an irreducible complex character of a finite group . A
well-known conjecture of D. Gluck claims that if is solvable then
. We confirm this conjecture in the case where
is coprime to 6. We also extend the problem to arbitrary finite groups and
prove several results showing that the largest irreducible character degree of
a finite group strongly controls the group structure.Comment: 16 page
The Largest Irreducible Representations of Simple Groups
Answering a question of I. M. Isaacs, we show that the largest degree of
irreducible complex representations of any finite non-abelian simple group can
be bounded in terms of the smaller degrees. We also study the asymptotic
behavior of this largest degree for finite groups of Lie type. Moreover, we
show that for groups of Lie type, the Steinberg character has largest degree
among all unipotent characters.Comment: 34 page
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