Centrala begrepp
The authors investigate the minimum acyclic number and maximum dichromatic number in oriented triangle-free graphs of a given order, providing bounds and constructions to support their findings.
Sammanfattning
The study explores the acyclic and dichromatic numbers in oriented triangle-free graphs, presenting bounds and constructions to demonstrate the results. The research delves into various aspects of graph theory, including Ramsey numbers, independence sets, chromatic numbers, and directed linear forests. The authors provide detailed proofs for their propositions and corollaries, showcasing the complexity of analyzing graph properties.
Key points include:
- Definition of acyclic number ⃗α(D) and dichromatic number ⃗χ(D) in digraphs.
- Investigation of minimum acyclic number ⃗a(n) and maximum dichromatic number ⃗t(n) in oriented triangle-free graphs.
- Bounds on ⃗a(n) and ⃗t(n) for large n values.
- Construction of oriented triangle-free graphs with specific dichromatic numbers.
- Application of results to specific graph structures like C5 and D25.
The research provides insights into fundamental properties of oriented graphs, offering valuable contributions to graph theory analysis.
Statistik
For every ε > 0 and n large enough, (1/√2 − ε)√n log n ≤ ⃗a(n) ≤ 107/8 √n log n
For every ε > 0 and n large enough, 8/107 √n/log n ≤ ⃗t(n) ≤ (√2 + ε)p/n/log n
Citat
"There is a factor of 4 between these upper and lower bounds on t(n)."
"Let D be a digraph. Its acyclic number α(D) is the maximum size of an acyclic set in D."