POLYNOMIAL RINGS OVER WEAK ARMENDARIZ RINGS NEED NOT BE WEAK ARMENDARIZ

摘要

It is proved that there exists a weak Armendriz ring R over which the polynomial ring R[x] is not weak Armendariz. This answers an open question of Liu and Zhao in 2006 in the negative, and eliminates the misunderstanding of the question having a positive solution by Hashemi in 2008.