TY - JOUR T1 - Cotorsion Dimension of Weak Crossed Products AU - Chen , Huaxi AU - Liang , Jinrong JO - Communications in Mathematical Research VL - 2 SP - 133 EP - 140 PY - 2019 DA - 2019/12 SN - 34 DO - http://doi.org/10.13447/j.1674-5647.2018.02.05 UR - https://global-sci.org/intro/article_detail/cmr/13519.html KW - weak crossed product, cotorsion dimension, projective resolution AB -

Let $H$ be a finite-dimensional weak Hopf algebra over a field $k$ and $A$ an associative algebra, and $A\#_{\sigma}H$ a weak crossed product. In this paper, a spectral sequence for Ext is constructed which yields an estimate for cotorsion dimension of $A\#_{\sigma}H$ in terms of the corresponding data for $H$ and $A$.