collaborators

7 papers

math.CO2019

On Star-critical (K1,n,K1,m + e) Ramsey numbers

C. J. Jayawardene, J. N. Senadheera, K. A. S. N. Fernando +1

Let be finite graphs without loops or multiple edges and denote the complete graph on vertices. If for every red/blue colouring of edges of the complete graph $K_n…

math.CO2019

On Star critical Ramsey numbers related to large cycles versus complete graphs

C. J. Jayawardene, W. C. W. Navaratna

Let denote the complete graph on vertices and be finite graphs. Consider a two-coloring of edges of . When a copy of in the first color, red, or a copy of…

math.CO2019

All Ramsey critical graphs for large

Chula J. Jayawardene, W. Chandanie W. Navaratna, J. N. Senadheera

Let and be finite graphs. If for any two-coloring of the edges of a complete graph , there is a copy of in the first color, red, or a copy of in the second col…

math.CO2019

Star-critical Ramsey numbers for cycles versus the complete graph on 5 vertices

Chula J. Jayawardene

Let , and represent three graphs without loops or parallel edges and represent an integer. Given any red blue coloring of the edges of , we say that $K \rightarro…

math.CO2019

A Ramsey problem related to butterfly graph vs. proper connected subgraphs of K4

Chula Jayawardene, Lilanthi Samarasekara

A graph on 5 vertices consisting of 2 copies of the cycle graph C3 sharing a common vertex is called the Butterfly graph (B). The smallest natural number s such that any two-colour…

math.CO2019

How Ramsey theory can be used to solve Harary's problem for

C. J. Jayawardene, C. C. Rousseau, B. Bollobás

Harary's conjecture for every isolated-free graph G with edges was proved independently by Sidorenko and Goddard and Klietman. In this paper instead of $C_3…