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1 vote
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378 views

Counting number of spanning trees of the complete bipartite with given vertex-degrees

For given $n_1,n_2 \in \mathbb{N}$ let $K_{n_1,n_2}$ be the complete bipartite graph. I have seen a few sources proving that the number of spanning trees $t(K_{n_1,n_2})$ is given by $n_1^{n_2-1} n_2^{...
Ben Deitmar's user avatar
  • 1,295
2 votes
1 answer
254 views

Is there a formula for the number of trees with this extra condition?

A tree $G$ on $n$ vertices $V=\{v_1,...,v_n\}$ is a connected undirected graph which is acyclic. For each tree $G$ one can split the set of vertices $V$ into two disjoint subsets $U,W \subset V$ such ...
Ben Deitmar's user avatar
  • 1,295
7 votes
0 answers
171 views

What is known about the distribution of lengths of the cycle you get by adding an edge to a uniform spanning tree?

Let $G$ be a finite, connected graph. Let $T$ be a uniform spanning tree, and let $e$ be a uniformly random edge not in $T$. When we add $e$ to $T$, we get a subgraph with a unique cycle, $C$. I am ...
Elle Najt's user avatar
  • 1,462
5 votes
1 answer
281 views

Transfer-impedance matrix for edge correlations in random spanning tree

Suppose $G$ is a (weighted) connected graph and let $T$ denote a random spanning tree of $G$, chosen uniformly (or respecting the edge weights). It is known that for any distinct edges $e, f$ $$\...
Harry Richman's user avatar
10 votes
2 answers
1k views

History of deletion-contraction formula

The following is known as deletion-contraction formula: Assume $\Gamma$ is a connectted graph with edge $\rho$ then $$t(\Gamma)=t(\Gamma\backslash\rho)+t(\Gamma/\rho),$$ where $\Gamma\backslash\...
Anton Petrunin's user avatar
6 votes
1 answer
643 views

Random path in a graph

Consider a finite graph $G$. I would like to define a random path between two vertices $s$ and $t$ of the graph $G$ by looking at a measure $\mu$ on all spanning trees. Then the probability of a given ...
ARG's user avatar
  • 4,422
2 votes
0 answers
1k views

Incremental minimum spanning tree

Given a connected graph $G=(V,E)$ with a weight function $w:E\to\mathbb{R}$ and a subset $E_0\subseteq E$ such that the subgraph $(V,E_0)$ is connected, I am looking for a sequence $E_0\subseteq E_1\...
Thomas Kalinowski's user avatar