The Critical Group of the Cone over a Sandwich Graph

The Critical Group of the Cone over a Sandwich Graph

Grunwald L. A.
Siberian Electronic Mathematical Reports, 22, 2, pp. 1255-1265 (2025)

УДК 517.5 
DOI: 10.33048/semi.2025.22.075  
MSC 35J05, 05C25


Abstract:

We study the critical group of the cone over a sandwich graph. It is shown that this group can be described as the cokernel of a discrete Laplace operator. Furthermore, we prove that its exact structure can be determined by making use of a recurrence relation derived from the Laplace operator. This relation involves symmetric Laurent polynomials and provides a more efficient way to compute the group. The proposed method offers a powerful tool for analyzing invariants of graphs with complex combinatorial structure.

Keywords: critical group, circulant graph, discrete Laplacian, Smith normal form.