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Questions tagged [regular-graph]

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5 votes
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How to construct 4-regular graphs with few Hamiltonian decompositions?

A Hamiltonian decomposition of a finite simple graph is a partition of its edge set so that each partition class forms a Hamiltonian cycle. This is only possible if the graph is $2k$-regular. ...
M. Winter's user avatar
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3 votes
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If the girth of a $2k$-regular graph $G$ is larger than the diameter of a tree $T$ with $k$ edges, then $G$ is decomposed into copies of $T$

I want to prove that ‘If the girth of a $2k$-regular graph $G$ is larger than the diameter of a $k$-edge tree $T$, then $G$ is covered by edge-disjoint copies of $T$.’ I tried several ways to solve ...
okw1124's user avatar
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Chromatic number of regular graphs using spectra

There exist inequalities relating the maximum and minimum eigenvalues of the adjacency matrix of a graph with its chromatic numbers, i.e. the Wilf's and Hoffmann's inequalities, which put together ...
vidyarthi's user avatar
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Random graphs constructed by many large matchings

Let $G_{n,d}$ be $d$-regular random graph. We know that for $d \geq 3$, $G \in G_{n,d}$ a.a.s. has a $1$-factorisation when $n$ is even. So, the resulting graph that obtained from randomly choosing $d$...
Yuhang Bai's user avatar
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A question related to contiguity of random regular graphs

I am looking for a reference for the following fact. Let $r\geq 3$ be constant, let $G(n,r-2)$ be a random (simple) $(r-2)$-regular graph and let $H(n)$ be an independent random Hamiltonian cycle (on ...
35T41's user avatar
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The diameter of random regular graphs

In 1982, B. Bollobas and Vega in the paper gave the configurational model to generate $r$-regular random graphs. They gave the following theorem (Theorem 1 in the paper). Theorem: Let $r\geq 3$ and $\...
Ranveer Singh's user avatar