On Betti numbers of edge ideals of crown graphs

Author(s):  
Shahnawaz Ahmad Rather ◽  
Pavinder Singh
Keyword(s):  
2019 ◽  
Vol 30 (01) ◽  
pp. 125-139
Author(s):  
Do Trong Hoang

We prove that [Formula: see text] for any staircase skew Ferrers graph [Formula: see text], where [Formula: see text] and [Formula: see text]. As a consequence, Ene et al. conjecture is confirmed to hold true for the Betti numbers in the last column of the Betti table in a particular case. An explicit formula for the unique extremal Betti number of the binomial edge ideal of some closed graphs is also given.


Author(s):  
Ajay Kumar ◽  
Pavinder Singh ◽  
Rohit Verma

In this paper, we obtain a combinatorial formula for computing the Betti numbers in the linear strand of edge ideals of bipartite Kneser graphs. We deduce lower and upper bounds for regularity of powers of edge ideals of these graphs in terms of associated combinatorial data and show that the lower bound is attained in some cases. Also, we obtain bounds on the projective dimension of edge ideals of these graphs in terms of combinatorial data.


10.37236/7689 ◽  
2018 ◽  
Vol 25 (1) ◽  
Author(s):  
Jürgen Herzog ◽  
Giancarlo Rinaldo

We compute one of the distinguished extremal Betti number of the binomial edge ideal of a block graph, and classify all block graphs admitting precisely one extremal Betti number.


10.37236/8810 ◽  
2020 ◽  
Vol 27 (2) ◽  
Author(s):  
Margherita Barile ◽  
Antonio Macchia

We present an explicit construction of minimal cellular resolutions for the edge ideals of forests, based on discrete Morse theory. In particular, the generators of the free modules are subsets of the generators of the modules in the Lyubeznik resolution. This procedure allows us to ease the computation of the graded Betti numbers and the projective dimension.


2020 ◽  
Vol 48 (12) ◽  
pp. 5026-5037
Author(s):  
Pavinder Singh ◽  
Rohit Verma

2012 ◽  
Author(s):  
Oscar Fernández Ramos

2021 ◽  
Vol 28 (03) ◽  
pp. 415-430
Author(s):  
Carla Mascia ◽  
Giancarlo Rinaldo

We provide the regularity and the Cohen–Macaulay type of binomial edge ideals of Cohen–Macaulay cones, and we show the extremal Betti numbers of some classes of Cohen–Macaulay binomial edge ideals: Cohen–Macaulay bipartite and fan graphs. In addition, we compute the Hilbert–Poincaré series of the binomial edge ideals of some Cohen–Macaulay bipartite graphs.


2017 ◽  
Vol 10 (03) ◽  
pp. 1750061
Author(s):  
Somayeh Moradi

In this paper, we study the regularity and the projective dimension of the Stanley–Reisner ring of a [Formula: see text]-decomposable simplicial complex and explain these invariants with a recursive formula. To this aim, the graded Betti numbers of decomposable monomial ideals which is the dual concept for [Formula: see text]-decomposable simplicial complexes are studied and an inductive formula for the Betti numbers is given. As a corollary, for a shellable simplicial complex [Formula: see text], a formula for the regularity of the Stanley–Reisner ring of [Formula: see text] is presented. Finally, for a chordal clutter [Formula: see text], an upper bound for [Formula: see text] is given in terms of the regularities of edge ideals of some chordal clutters which are minors of [Formula: see text].


Sign in / Sign up

Export Citation Format

Share Document