Abstract
We conjecture a strong property for the up and down maps U and D in an r-differential poset: DU + tI and UD + tI have Smith normal forms over z[t]. In particular, this would determine the integral structure of the maps U, D, UD, DU, including their ranks in any characteristic. As evidence, we prove the conjecture for the Young-Fibonacci lattice YF studied by Okada and its r-differential generalizations Z(r), as well as verifying many of its consequences for Young's lattice Y and the r-differential Cartesian products Yr.
Original language | English (US) |
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Pages (from-to) | 197-228 |
Number of pages | 32 |
Journal | Order |
Volume | 26 |
Issue number | 3 |
DOIs | |
State | Published - Sep 2009 |
Keywords
- Differential poset
- Dual graded graphs
- Invariant factors
- Smith normal form