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Generalized Matrix polynomials of Tree Laplacians indexed by Symmetric functions and the GTS poset

Combinatorics 2024-07-09 v1

Abstract

Let TT be a tree on nn vertices with qq-Laplacian LTqL_T^q and Laplacian matrix LTL_T. Let GTSnGTS_n be the generalized tree shift poset on the set of unlabelled trees on nn vertices. Inequalities are known between coefficients of the immanantal polynomial of LTL_T (and LTqL_T^q) as we go up the poset GTSnGTS_n. Using the Frobenius characteristic, this can be thought as a result involving the schur symmetric function sλs_{\lambda}. In this paper, we use an arbitrary symmetric function to define a {\it generalized matrix function} of an n×nn \times n matrix. When the symmetric function is the monomial and the forgotten symmetric function, we generalize such inequalities among coefficients of the generalized matrix polynomial of LTqL_T^q as we go up the GTSnGTS_n poset.

Keywords

Cite

@article{arxiv.1912.03101,
  title  = {Generalized Matrix polynomials of Tree Laplacians indexed by Symmetric functions and the GTS poset},
  author = {Mukesh Kumar Nagar and Sivaramakrishnan Sivasubramanian},
  journal= {arXiv preprint arXiv:1912.03101},
  year   = {2024}
}

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11 pages