Abstract
We consider two problems regarding vanishing patterns in the Betti table of edge ideals I over any fixed field. First, we show that the j-strand is connected if j= 3 (for j= 2 this is easy and known), and give examples where the j-strand is not connected for any j> 3. Next, we apply our result on strand connectivity to establish the subadditivity conjecture for edge ideals, ta + b(I) ≤ ta(I) + tb(I) , in case b= 2 , 3 (the case b= 1 is known). Here ti(I) denote the maximal shifts in the minimal free resolution of S / I over its polynomial algebra.
Original language | English |
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Pages (from-to) | 287-295 |
Number of pages | 9 |
Journal | Journal of Algebraic Combinatorics |
Volume | 46 |
Issue number | 2 |
DOIs | |
State | Published - 1 Sep 2017 |
Bibliographical note
Publisher Copyright:© 2017, Springer Science+Business Media New York.
Keywords
- Betti diagram
- Edge ideal
- Monomial ideal
- Simplicial complex
- Subadditivity