• Journal for History of Mathematics
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• v.18 no.1
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• pp.75-84
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• 2005

In this paper, we know the historical background in group representations and prove the properties such that a finite group G has non-trivial abelian normal subgroup in some condition for the irreducible character G and prove the properties of product of irreducible characters of finite groups.

• Journal for History of Mathematics
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• v.13 no.2
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• pp.151-160
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• 2000

In this paper we prove that for all irreducible complex characters of a finite group, there exist F-representations and a finite degree field extension F ⊇ Q, where Q is the rational number field.

• Communications of the Korean Mathematical Society
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• v.18 no.2
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• pp.215-223
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• 2003

Parks [7] showed that there is an one to one correspondence between good pairs of subgroups in G and irreducible monomial characters of G. This provides a useful criterion for a group to be monomial. In this paper, we study relative monomial groups by defining triples in G, and find relationships between the triples and irreducible relative monomial characters.

• Journal of applied mathematics & informatics
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• v.4 no.1
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• pp.193-210
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• 1997

In this paper we find the irreducible complex characters of the automorphism group of the general linear group of degree 7 over a field with two elements. It is shown that this group has 114 irreducible complex characters.

• Journal for History of Mathematics
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• v.15 no.2
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• pp.169-174
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• 2002

In this paper we prove that tile property of product irreducible characters is, if $\Phi$$\in$$\textit{Irr(H)}$ and $\Theta$$\in$$\textit{Irr(K)}$ are faithful, then $\Phi$$\times\theta$ is faithful if and only if │$\textit{Z(H)}$│ and │$\textit{Z(K)}$│ are relative primes where G=$\textit{H}\times\textit{K}$.

• Journal of the Korean Mathematical Society
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• v.26 no.2
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• pp.291-300
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• 1989

• Communications of the Korean Mathematical Society
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• v.34 no.1
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• pp.137-143
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• 2019

In this paper, we show that $A_4$ is the only finite group with exactly two conjugacy classes of the same size having some non-real linear characters.

• Bulletin of the Korean Mathematical Society
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• v.60 no.6
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• pp.1497-1522
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• 2023

In this paper we compute the Bredon homology of wallpaper groups with respect to the family of finite groups and with coefficients in the complex representation ring. We provide explicit bases of the homology groups in terms of irreducible characters of the stabilizers.

• Journal of the Korean Mathematical Society
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• v.57 no.5
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• pp.1187-1237
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• 2020

Simply reducible groups are important in physics and chemistry, which contain some of the important groups in condensed matter physics and crystal symmetry. By studying the group structures and irreducible representations, we find some new examples of simply reducible groups, namely, dihedral groups, some point groups, some dicyclic groups, generalized quaternion groups, Heisenberg groups over prime field of characteristic 2, some Clifford groups, and some Coxeter groups. We give the precise decompositions of product of irreducible characters of dihedral groups, Heisenberg groups, and some Coxeter groups, giving the Clebsch-Gordan coefficients for these groups. To verify some of our results, we use the computer algebra systems GAP and SAGE to construct and get the character tables of some examples.

• Journal of the Korean Mathematical Society
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• v.34 no.2
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• pp.453-467
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• 1997

A transitive permutation representation of a group G is said to be multiplicity-free if all of its irreducible constituents are distinct. The character corresponding to the action is called the permutation character, given by $(1_H)^G$, where H is the stabilizer of a point. Multiplicity-free permutation characters are of interest in the study of centralizer algebras and distance-transitive graphs, and all finite simple groups are known to have such characters. In this article, we extend to the alternating groups the result of J. Saxl who determined the multiplicity-free permutation representations of the symmetric groups. We classify all subgroups H for which $(1_H)^An, n > 18$, is multiplicity-free.