Eisenstein extension, connectedness and the second vanishing theorem
Abstract
In this paper, at first, we show that for a ramified regular local ring , which is an Eisenstein extension of an unramified regular local ring , when an ideal of is extended from an ideal of , the punctured spectrum of is connected if that of is connected. Using this, we extend the result of SVT to complete ramified regular local ring only for the extended ideals. If the punctured spectrum of is disconnected then that of is also disconnected when every minimal primes of , is normal. Under this situation we prove that both of them have the same number of connected components. Finally, we show that for both unramified and ramified regular local rings (for extended ideal via Eisenstein extension), two top-most local cohomology modules satisfy the Conjecture 1 of \cite{L-Y}, although the conjecture is false in general.
Cite
@article{arxiv.2004.02075,
title = {Eisenstein extension, connectedness and the second vanishing theorem},
author = {Rajsekhar Bhattacharyya},
journal= {arXiv preprint arXiv:2004.02075},
year = {2024}
}
Comments
8 pages, results are improved and reference added