2 papers
math.CO2026
Characteristic Polynomials of Graph- and Digraph-Deleted Catalan Arrangements
Yanru Chen, Ang Li, Suijie Wang
We develop a finite-field stratification for characteristic polynomials of deletion subarrangements of the full -Catalan arrangement. It reduces the count to cyclic placements o…
math.CO2026
Convolution-type Identity for Characteristic Polynomials of Geometric Semilattices
Yanru Chen, Houshan Fu, Ang Li +1
We establish a convolution formula for the characteristic polynomial of a finite geometric semilattice : \[ Ï(M,st)=\sum_{X\in \underline{M}} s^{r-{\rm rk}_{\underline{M}}(X)}Ï…