Semi-invariant Matrices over Finite Groups

Simple Twisted Group Algebras of Dimensionp4and their Semi-Centers

“…Proposition 2.7 which gives a complete description of the weight spaces (C f G) λ , and Lemma 2.8 claiming that any central element in G induce a semi-invariant element in C f G were both proven in [12].…”

“…Evidently, the size of any group of central type is a square. It turns out that twisted group algebras and groups of central type play a major role in the understanding of other algebraic objects, as graded algebras (see [3], [10], [11]), semi-invariants of matrices (see [12]) and twisted category algebras (see [7], [15]).…”

“…[18,21,22]. In [12] Y. Ginosar and the author generalized a result of D. Passman and P. Wauters (see [18]), by showing that if the Artin-Wedderburn de-…”

“…(see[12, Corollary 6.5]) For any f ∈ Z 2 (G, C * ), letΓ(f ) = λ∈Ĝ Γ(λ, f )be a set of representatives of the (λ, f )-regular conjugacy classes for all λ ∈Ĝ. Then…”

Units of twisted group rings and their correlations to classical group rings

“…In Section 5.2 we will consider various such normal subgroups Q and the (co)kernel of the transgression map associated to Γ/Q. Therefore we also write Tra Q for the transgression map associated to the abelian extension (6). When the extension or Q are clear from the context we write Tra.…”