English

Behaviour of the Support of Lyubeznik Functors under Ring Extensions

Commutative Algebra 2015-12-19 v1

Abstract

Let RSR\rightarrow S be an arbitrary ring extension of Noetherian rings. In this article we study the behaviour of Zariski closedness of the support of Lyubeznik functors T\mathrm{T}, when the ring extension RSR\rightarrow S is namely `flat', `faithfully flat', `pure' and lastly `cyclically pure'. We show that the Zariski closedness of the support comes down from extended ring to the base ring for faithfully flat, pure and finally for cyclically pure ring extensions. Lastly, we focus on a special case of pure extension i.e. when RR is a direct summand of SS and we compare the sets SuppS(T(R)RS)\mathrm{Supp}_S(\mathrm{T}(R)\otimes_R S) and SuppST(S)\mathrm{Supp}_S \mathrm{T}(S).

Keywords

Cite

@article{arxiv.1512.05678,
  title  = {Behaviour of the Support of Lyubeznik Functors under Ring Extensions},
  author = {Rajsekhar Bhattacharyya},
  journal= {arXiv preprint arXiv:1512.05678},
  year   = {2015}
}

Comments

16 pages. arXiv admin note: text overlap with arXiv:1512.05672