منابع مشابه
Category O over Skew Group Rings
We study the BGG Category O over a skew group ring, involving a finite group acting on a regular triangular algebra. We relate the representation theory of the algebra to Clifford theory for the skew group ring, and obtain results on block decomposition, semisimplicity, and enough projectives. O is also shown to be a highest weight category; the BGG Reciprocity formula is slightly different bec...
متن کاملMaximal Crossed Product Orders over Discrete Valuation Rings
The problem of determining when a (classical) crossed product T = S ∗ G of a finite group G over a discrete valuation ring S is a maximal order, was answered in the 1960’s for the case where S is tamely ramified over the subring of invariants S. The answer was given in terms of the conductor subgroup (with respect to f) of the inertia. In this paper we solve this problem in general when S/S is ...
متن کاملOn Azumaya Galois Extensions and Skew Group Rings
Two characterizations of an Azumaya Galois extension of a ring are given in terms of the Azumaya skew group ring of the Galois group over the extension and a Galois extension of a ring with a special Galois system is determined by the trace of the Galois group.
متن کاملHyperbolicity of orders of quaternion algebras and group rings
For a given division algebra of the quaternions, we construct two types of units of its Z-orders: Pell units and Gauss units. Also, if K = Q √ −d, d ∈ Z \ {0, 1} is square free and R = IK , we classify R and G such that U1(RG) is hyperbolic. In particular, we prove that U1(RK8) is hyperbolic iff d > 0 and d ≡ 7 (mod 8). In this case, the hyperbolic boundary ∂(U1(RG)) ∼= S, the two dimensional s...
متن کاملJa n 20 06 CATEGORY O OVER SKEW GROUP RINGS
We study the BGG Category O over a skew group ring, involving a finite group acting on a regular triangular algebra. We relate the representation theory of the algebra to Clifford theory for the skew group ring, and obtain results on block decomposition, semisimplicity, and enough projectives. O is also shown to be a highest weight category; the BGG Reciprocity formula is slightly different bec...
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ژورنال
عنوان ژورنال: Glasgow Mathematical Journal
سال: 1995
ISSN: 0017-0895,1469-509X
DOI: 10.1017/s0017089500031153