Krull–Schmidt decompositions for thick subcategories

AbstractFollowing H. Krause [Decomposing thick subcategories of the stable module category, Math. Ann. 313 (1) (1999) 95–108], we prove Krull–Schmidt type decomposition theorems for thick subcategories of various triangulated categories including the derived categories of rings, Noetherian stable homotopy categories, stable module categories over Hopf algebras, and the stable homotopy category of spectra. In all these categories, it is shown that the thick ideals of small objects decompose uniquely into indecomposable thick ideals. We also discuss some consequences of these decomposition results. In particular, it is shown that all these decompositions respect K-theory