Abstract
A ring extension is said to have depth one if is isomorphic to a direct summand of as an -bimodule, for some positive integer . We prove group-theoretic characterizations of this property in the case , where is a subgroup of a finite group and is a field. We determine when the source algebra of a block of with defect group is a depth-one extension of .
Citation
Robert Boltje. Burkhard Külshammer. "Group algebra extensions of depth one." Algebra Number Theory 5 (1) 63 - 73, 2011. https://doi.org/10.2140/ant.2011.5.63
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