836 research outputs found

    Ramsey numbers of color critical graphs versus large generalized fans

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    Given two graphs GG and HH, the {Ramsey number} R(G,H)R(G,H) is the smallest positive integer NN such that every 2-coloring of the edges of KNK_{N} contains either a red GG or a blue HH. Let KN1K1,kK_{N-1}\sqcup K_{1,k} be the graph obtained from KN1K_{N-1} by adding a new vertex vv connecting kk vertices of KN1K_{N-1}. Hook and Isaak (2011) defined the {\em star-critical Ramsey number} r(G,H)r_{*}(G,H) as the smallest integer kk such that every 2-coloring of the edges of KN1K1,kK_{N-1}\sqcup K_{1,k} contains either a red GG or a blue HH, where N=R(G,H)N=R(G, H). For sufficiently large nn, Li and Rousseau~(1996) proved that R(Kk+1,K1+nKt)=knt+1R(K_{k+1},K_{1}+nK_{t})=knt +1, Hao, Lin~(2018) showed that r(Kk+1,K1+nKt)=(k1)tn+tr_{*}(K_{k+1},K_{1}+nK_{t})=(k-1)tn+t; Li and Liu~(2016) proved that R(C2k+1,K1+nKt)=2nt+1R(C_{2k+1}, K_{1}+nK_{t})=2nt+1, and Li, Li, and Wang~(2020) showed that r(C2m+1,K1+nKt)=nt+tr_{*}(C_{2m+1},K_{1}+nK_{t})=nt+t. A graph GG with χ(G)=k+1\chi(G)=k+1 is called edge-critical if GG contains an edge ee such that χ(Ge)=k\chi(G-e)=k. In this paper, we extend the above results by showing that for an edge-critical graph GG with χ(G)=k+1\chi(G)=k+1, when k2k\geq 2, t2t\geq 2 and nn is sufficiently large, R(G,K1+nKt)=knt+1R(G, K_{1}+nK_{t})=knt+1 and r(G,K1+nKt)=(k1)nt+tr_{*}(G,K_{1}+nK_{t})=(k-1)nt+t.Comment: 10 page

    Small Ramsey Numbers

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    We present data which, to the best of our knowledge, includes all known nontrivial values and bounds for specific graph, hypergraph and multicolor Ramsey numbers, where the avoided graphs are complete or complete without one edge. Many results pertaining to other more studied cases are also presented. We give references to all cited bounds and values, as well as to previous similar compilations. We do not attempt complete coverage of asymptotic behavior of Ramsey numbers, but concentrate on their specific values

    THE ELECTRONIC JOURNAL OF COMBINATORICS (2014), DS1.14 References

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    and Computing 11. The results of 143 references depend on computer algorithms. The references are ordered alphabetically by the last name of the first author, and where multiple papers have the same first author they are ordered by the last name of the second author, etc. We preferred that all work by the same author be in consecutive positions. Unfortunately, this causes that some of the abbreviations are not in alphabetical order. For example, [BaRT] is earlier on the list than [BaLS]. We also wish to explain a possible confusion with respect to the order of parts and spelling of Chinese names. We put them without any abbreviations, often with the last name written first as is customary in original. Sometimes this is different from the citations in other sources. One can obtain all variations of writing any specific name by consulting the authors database of Mathematical Reviews a

    Advances in Discrete Applied Mathematics and Graph Theory

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    The present reprint contains twelve papers published in the Special Issue “Advances in Discrete Applied Mathematics and Graph Theory, 2021” of the MDPI Mathematics journal, which cover a wide range of topics connected to the theory and applications of Graph Theory and Discrete Applied Mathematics. The focus of the majority of papers is on recent advances in graph theory and applications in chemical graph theory. In particular, the topics studied include bipartite and multipartite Ramsey numbers, graph coloring and chromatic numbers, several varieties of domination (Double Roman, Quasi-Total Roman, Total 3-Roman) and two graph indices of interest in chemical graph theory (Sombor index, generalized ABC index), as well as hyperspaces of graphs and local inclusive distance vertex irregular graphs

    Resolutely Inclusive: Merz Art Practice and Einfühlung

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    Through creative practice and exegetical writing this research investigates a possibility for continual engagement in aesthetic appreciation and a particular way of noticing that artists and viewers of artwork may share. Merz, invented by artist Kurt Schwitters, is a type of accumulative art practice that could include any material or method. Viewing and producing this type of artwork is examined via a theory of aesthetic appreciation called Einfühlung: a study of spectator’s embodied experiences with aesthetic works
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