Cohomology theory of finite groups

块理想是有限群表示论的主要研究对象。本文利用块理想的源代数刻画了块理想的上同调环。源代数是块理想的重要不变量。我们给出了分析源代数的上同调判据。将这些结果应用于Tame表示型的块理想，我们研究了上同调环和源代数。

Block ideals are main objects to be investigated in representation theory of finite groups. In this study we gave a characterization of cohomology rings of block ideal in terms of source algebras of block ideals. Source algebras are so important invariants of block ideals. However it is so hard to treat with them; we gave a cohomological criterion for analyzing source algebras. Applying these results to block ideals of tame representation type, we investigated cohomology rings and source algebras.