We prove the $\Delta$-conjecture, which dates back to Gurvich's 1978 thesis. Specifically, let the edges of a complete graph be colored with colors $1,\ldots,d$, and for each $i$ let $G_i$ be the graph on the same vertex set formed by the edges of color $i$. We prove that if every choice of a maximal stable set $S_i$ o...
For an integer $k\ge2$, let $\lambda_k(G)$ denote the $k$th largest adjacency eigenvalue of a graph $G$. For every graph $G$ on $n$ vertices and every $2 \leq k \leq n$, we prove \[ \lambda_k(G) \le \frac{(k-2)\sqrt{k+1}+2}{2k(k-1)}\,n-1. \] Our bound is tight for $k\in\{2,3,4,8,24\}$. We obtain it by reducing the grap...
We answer a problem posed by Matilde Lal\'in concerning the areal Mahler measures of the multivariable polynomial family $$ P_n(x_1,\ldots,x_n,u) = \prod_{j=1}^n(1+x_j) + u\prod_{j=1}^n(1-x_j), \qquad n\geq1. $$ Using a probabilistic reformulation, we derive convolution and one-dimensional Fourier integral representati...
Quanyu Tang, Shu Zhang· 0 citations
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