Thilo Hartel

works on

cyclic neighborhoods 1 directed graphs 1 edge density 1 extremal graph theory 1 strong connectivity 1

From the 1 of 3 linked papers with an AI index.

collaborators

3 papers

math.CO2026

Cyclic Neighborhoods in Digraphs

Thilo Hartel, Dieter Rautenbach

The paper proves that any strongly connected digraph where every vertex’s in‑ or out‑neighbourhood contains a directed cycle must have at least 7n/3 edges, and if the digraph is st…

math.CO2026

Degenerate Vertex Cuts in Sparse Graphs

Thilo Hartel, Johannes Rauch, Dieter Rautenbach

For a non-negative integer $k$ , a vertex cut in a graph is $k$ -degenerate if it induces a $k$ -degenerate subgraph. We show that a graph of order $n$ at least $2 k + 2$ without a $k$ -d…

math.CO2025

On the number of maximal independent sets and maximal induced bipartite subgraphs in $K_{4}$ -free graphs

Thilo Hartel, Lucas Picasarri-Arrieta, Dieter Rautenbach

Let $G$ be a $K_{4}$ -free graph of order $n$ and let $k$ be an integer with $0 \leq k \leq n$ . We show the existence of positive constants $I^\cdot$ and $I^½$ such that $G$ has at most $(4-Î…

Cyclic Neighborhoods in Digraphs

Degenerate Vertex Cuts in Sparse Graphs

On the number of maximal independent sets and maximal induced bipartite subgraphs in K4​-free graphs

On the number of maximal independent sets and maximal induced bipartite subgraphs in $K_{4}$ -free graphs