Let G be a nonabelian finite group. Then Irr(G/G’) is an abelian group under the multiplication of characters and acts on the set of non-linear irreducible characters of G via the multiplication of characters. The pu...Let G be a nonabelian finite group. Then Irr(G/G’) is an abelian group under the multiplication of characters and acts on the set of non-linear irreducible characters of G via the multiplication of characters. The purpose of this paper is to establish some facts about the action of linear character group on non-linear irreducible characters and determine the structures of groups G for which either all the orbit kernels are trivial or the number of orbits is at most two. Using the established results on this action, it is very easy to classify groups G having at most three non-linear irreducible characters.展开更多
Column closed pattern subgroups U of the finite upper unitriangular groups U_n(q) are defined as sets of matrices in U_n(q) having zeros in a prescribed set of columns besides the diagonal ones. We explain Jedlitschky...Column closed pattern subgroups U of the finite upper unitriangular groups U_n(q) are defined as sets of matrices in U_n(q) having zeros in a prescribed set of columns besides the diagonal ones. We explain Jedlitschky's construction of monomial linearisation in his thesis and apply this to CU yielding a generalisation of Yan's coadjoint cluster representations. Then we give a complete classification of the resulting supercharacters,by describing the resulting orbits and determining the Hom-spaces between orbit modules.展开更多
Let X be a metric space, f∈ C0(X), and V X. The set-trajectory ( V, f( V),…,fn(V)) is investigated and some conditions for f to have periodic points with given periods are obtained.
基金Project supported by the National Natural Science Foundation of China (No.19771013).
文摘Let G be a nonabelian finite group. Then Irr(G/G’) is an abelian group under the multiplication of characters and acts on the set of non-linear irreducible characters of G via the multiplication of characters. The purpose of this paper is to establish some facts about the action of linear character group on non-linear irreducible characters and determine the structures of groups G for which either all the orbit kernels are trivial or the number of orbits is at most two. Using the established results on this action, it is very easy to classify groups G having at most three non-linear irreducible characters.
基金supported by National Natural Science Foundation of China(Grant No.11601338)the German Research Foundation,Priority Programme Deutsche ForschungsgemeinschaftSchwerpunktsprogramm Darstellungstheorie 1388 in Representation Theory(Grant No.99028426)
文摘Column closed pattern subgroups U of the finite upper unitriangular groups U_n(q) are defined as sets of matrices in U_n(q) having zeros in a prescribed set of columns besides the diagonal ones. We explain Jedlitschky's construction of monomial linearisation in his thesis and apply this to CU yielding a generalisation of Yan's coadjoint cluster representations. Then we give a complete classification of the resulting supercharacters,by describing the resulting orbits and determining the Hom-spaces between orbit modules.
基金the Special Foundation of National Prior Basic Researches of China ( Grant No. G1999075108).
文摘Let X be a metric space, f∈ C0(X), and V X. The set-trajectory ( V, f( V),…,fn(V)) is investigated and some conditions for f to have periodic points with given periods are obtained.
