Symbolic powers, Serre conditions and Cohen-Macaulay Rees algebras

1995 ◽  
Vol 86 (1) ◽  
pp. 113-124 ◽  
Author(s):  
Susan Morey ◽  
Sunsook Noh ◽  
Wolmer V. Vasconcelos
Author(s):  
Jonathan Montaño ◽  
Luis Núñez-Betancourt

Abstract We study the symbolic powers of square-free monomial ideals via symbolic Rees algebras and methods in prime characteristic. In particular, we prove that the symbolic Rees algebra and the symbolic associated graded algebra are split with respect to a morphism that resembles the Frobenius map and that exists in all characteristics. Using these methods, we recover a result by Hoa and Trung that states that the normalized $a$-invariants and the Castelnuovo–Mumford regularity of the symbolic powers converge. In addition, we give a sufficient condition for the equality of the ordinary and symbolic powers of this family of ideals and relate it to Conforti–Cornuéjols conjecture. Finally, we interpret this condition in the context of linear optimization.


2005 ◽  
Vol 302 (1-3) ◽  
pp. 7-21 ◽  
Author(s):  
Adrián Alcántar
Keyword(s):  

Author(s):  
Arvind Kumar ◽  
Rajiv Kumar ◽  
Rajib Sarkar ◽  
S. Selvaraja
Keyword(s):  

2017 ◽  
Vol 69 (1) ◽  
pp. 293-309
Author(s):  
Naoki TANIGUCHI ◽  
Tran Thi PHUONG ◽  
Nguyen Thi DUNG ◽  
Tran Nguyen AN
Keyword(s):  

2011 ◽  
Vol 34 (1) ◽  
pp. 221-227 ◽  
Author(s):  
Nguyên Công MINH ◽  
Yukio NAKAMURA
Keyword(s):  

1979 ◽  
Vol 19 (2) ◽  
pp. 327-333 ◽  
Author(s):  
Yasuhiro Shimoda

2017 ◽  
Vol 120 (1) ◽  
pp. 5 ◽  
Author(s):  
S. A. Seyed Fakhari

The aim of this paper is to study the Stanley depth of symbolic powers of a squarefree monomial ideal. We prove that for every squarefree monomial ideal $I$ and every pair of integers $k, s\geq 1$, the inequalities $\mathrm{sdepth} (S/I^{(ks)}) \leq \mathrm{sdepth} (S/I^{(s)})$ and $\mathrm{sdepth}(I^{(ks)}) \leq \mathrm{sdepth} (I^{(s)})$ hold. If moreover $I$ is unmixed of height $d$, then we show that for every integer $k\geq1$, $\mathrm{sdepth}(I^{(k+d)})\leq \mathrm{sdepth}(I^{{(k)}})$ and $\mathrm{sdepth}(S/I^{(k+d)})\leq \mathrm{sdepth}(S/I^{{(k)}})$. Finally, we consider the limit behavior of the Stanley depth of symbolic powers of a squarefree monomial ideal. We also introduce a method for comparing the Stanley depth of factors of monomial ideals.


Author(s):  
Yan Gu ◽  
Huy Tài Hà ◽  
Joseph W. Skelton

We show that attaching a whisker (or a pendant) at the vertices of a cycle cover of a graph results in a new graph with the following property: all symbolic powers of its cover ideal are Koszul or, equivalently, componentwise linear. This extends previous work where the whiskers were added to all vertices or to the vertices of a vertex cover of the graph.


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