Academic Journal

2-Reachable Subsets in Two-Colored Graphs

Λεπτομέρειες βιβλιογραφικής εγγραφής
Τίτλος: 2-Reachable Subsets in Two-Colored Graphs
Συγγραφείς: Gyárfás, András, Sárközy, Gábor N.
Στοιχεία εκδότη: Springer
Έτος έκδοσης: 2026
Συλλογή: MTAK: REAL (Library and Information Centre of the Hungarian Academy of Sciences / Magyar Tudományos Akadémia Könyvtár és Információs Központ)
Θεματικοί όροι: QA166-QA166.245 Graphs theory / gráfelmélet
Περιγραφή: A subset X of vertices in a graph G is a diameter 2 subset if the distance of any two vertices of X is at most two in G[X] . Relaxing this notion, a subset X of vertices in a graph G is a 2-reachable subset if the distance of any two vertices of X is at most two in G . Related to recent attempts to strengthen a well-known conjecture of Ryser, English et al. conjectured that the vertices of a 2-edge-colored cocktail party graph (the graph obtained from a complete graph with an even number of vertices by deleting a perfect matching) can be covered by the vertices of two monochromatic diameter 2 subsets. In this note we prove the relaxed form of this conjecture, replacing diameter 2 by 2-reachable. An immediate corollary is that 2-colored cocktail party graphs on n vertices must contain a monochromatic 2-reachable subset with at least n\over 2 n 2 vertices (and this is best possible).
Τύπος εγγράφου: article in journal/newspaper
Περιγραφή αρχείου: text
Γλώσσα: English
ISSN: 0911-0119
Relation: https://real.mtak.hu/237037/1/s00373-026-03036-6.pdf; Gyárfás, András and Sárközy, Gábor N. (2026) 2-Reachable Subsets in Two-Colored Graphs. GRAPHS AND COMBINATORICS, 42. ISSN 0911-0119
DOI: 10.1007/s00373-026-03036-6
Διαθεσιμότητα: https://real.mtak.hu/237037/
https://doi.org/10.1007/s00373-026-03036-6
Rights: cc_by
Αριθμός Καταχώρησης: edsbas.60159BDB
Βάση Δεδομένων: BASE