Abstract
It has been conjectured by Cowan and Emerson [3] that every graph has an unfriendly partition; i.e., there is a partition of the vertex set V = V0 {smile} V1 such that every vertex of Vi is joined to at least as many vertices in V1-i as to vertices in Vi. It is easily seen that every finite graph has such a partition, and hence by compactness so does any locally finite graph. We show that the conjecture is also true for graphs which satisfy one of the following two conditions: (i) there are only finitely many vertices having infinite degrees; (ii) there are a finite number of infinite cardinals m0 < m1 < ... < mk such that mi is regular for 1 ≤ i ≤ k, there are fewer than m0 vertices having finite degrees, and every vertex having infinite degree has degree mi for some i ≤ k.
Original language | English (US) |
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Pages (from-to) | 1-10 |
Number of pages | 10 |
Journal | Journal of Combinatorial Theory, Series B |
Volume | 50 |
Issue number | 1 |
DOIs | |
State | Published - Oct 1990 |
Bibliographical note
Funding Information:when the first and by NSERC Grant