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math.CO2026
An Odd Pfaffian Number
Priyanshu Pant, Ranveer Singh
The Pfaffian number of a graph is the minimum number of Pfaffians needed to obtain its perfect-matching polynomial by linear combination. In 2009, Norine conjectured that every Pfa…
math.CO2026
Exponential Lower Bounds for the Pfaffian Number of Graphs
Priyanshu Pant, Ranveer Singh
Galluccio--Loebl and Tesler showed that the perfect-matching polynomial of a graph embedded in an orientable surface of genus can be written as a linear combination of at most…
math.CO2026
Structural Classes for Chollet's Permanent Conjecture
Priyanshu Pant, Ranveer Singh
In 1982, Chollet conjectured that for Hermitian positive semidefinite matrices , where de…
math.CO2026
Permanental Energy of Graphs
Priyanshu Pant, Ranveer Singh
For a simple graph with adjacency matrix , let be its permanental polynomial with roots , and define the pe…