Two cycle-chord graphs are -positive
arXiv:2112.06679
Abstract
We prove Gebhard and Sagan's -positivity of the line graphs of tadpoles in noncommuting variables. This implies the -positivity of these line graphs. We then extend this -positivity result to that of certain cycle-chord graphs, and derive the bivariate generating function of all cycle-chord graphs.
15 pages, 4 figures