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Register a new userWeakly Distinguishing Graph Polynomials on Addable Properties
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A graph polynomial $P$ is weakly distinguishing if for almost all finite graphs $G$ there is a finite graph $H$ that is not isomorphic to $G$ with $P(G)=P(H)$. It is weakly distinguishing on a graph property $mathcal{C}$ if for almost all finite graphs $Ginmathcal{C}$ there is $H in mathcal{C}$ that is not isomorphic to $G$ with $P(G)=P(H)$. We give sufficient conditions on a graph property $mathcal{C}$ for the characteristic, clique, independence, matching, and domination and $xi$ polynomials, as well as the Tutte polynomial and its specialisations, to be weakly distinguishing on $mathcal{C}$. One such condition is to be addable and small in the sense of C. McDiarmid, A. Steger and D. Welsh (2005). Another one is to be of genus at most $k$.
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By considering the parity of the degrees and levels of nodes in increasing trees, a new combinatorial interpretation for the coefficients of the Taylor expansions of the Jacobi elliptic functions is found. As one application of this new interpretation, a conjecture of Ma-Mansour-Wang-Yeh is solved. Unifying the concepts of increasing trees and plane trees, Lin-Ma-Ma-Zhou introduced weakly increasing trees on a multiset. A symmetry joint distribution of even-degree nodes on odd levels and odd-degree nodes on weakly increasing trees is found, extending the Schett polynomials, a generalization of the Jacobi elliptic functions introduced by Schett, to multisets. A combinatorial proof and an algebraic proof of this symmetry are provided, as well as several relevant interesting consequences. Moreover, via introducing a group action on trees, we prove the partial $gamma$-positivity of the multiset Schett polynomials, a result implies both the symmetry and the unimodality of these polynomials.
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