Results 61 to 70 of about 4,692 (164)
Bipartite Ramsey numbers of large cycles
, 2018 For an integer $r\geq 2$ and bipartite graphs $H_i$, where $1\leq i\leq r$, the bipartite Ramsey number $br(H_1,H_2,\ldots,H_r)$ is the minimum integer $N$ such that any $r$-edge coloring of the complete bipartite graph $K_{N,N}$ contains a monochromatic subgraph isomorphic to $H_i$ in color $i$ for some $i$, $1\leq i\leq r$.
Liu, Shaoqiang, Peng, Yuejian
openaire +2 more sources
, 2013 I state some open problems coming from joint work with Paul Erd\H{o}sComment: This is a paper form of the talk I gave on July 5, 2013 at the centennial conference in Budapest to honor Paul Erd\H{o}
Gyárfás, András
core
Fixed-Parameter Tractability of Token Jumping on Planar Graphs
, 2015 Suppose that we are given two independent sets $I_0$ and $I_r$ of a graph such that $|I_0| = |I_r|$, and imagine that a token is placed on each vertex in $I_0$. The token jumping problem is to determine whether there exists a sequence of independent sets
AE Mouawad +12 more
core +1 more source
Journal of Quaternary Science, Volume 40, Issue 5, Page 778-793, July 2025.ABSTRACT Northwest Europe experienced high‐amplitude climate change at the onset and end of the Younger Dryas (YD; ca 12 800–11 600 cal a BP), a crucial period to develop our understanding of natural climate dynamics. European palaeoclimatological records generally suggest a bipartite structure of the YD, potentially due to a northward retreat of the ...
Christopher P. Francis +5 more
wiley +1 more source
Essentially tight bounds for rainbow cycles in proper edge‐colourings
Proceedings of the London Mathematical Society, Volume 130, Issue 4, April 2025.Abstract An edge‐coloured graph is said to be rainbow if no colour appears more than once. Extremal problems involving rainbow objects have been a focus of much research over the last decade as they capture the essence of a number of interesting problems in a variety of areas.
Noga Alon +4 more
wiley +1 more source
Journal of Systematics and Evolution, Volume 63, Issue 2, Page 319-330, March 2025.Using phylogenomics and allele frequency‐based approach based on multiple plastid and low‐copy nuclear genes, we confirm the hybrid origin of Dactylorhiza cantabrica, an endemic allopolyploid orchid from north‐western Iberia, as well as the clear genetic differentiation of the two parental species.
Eva Pardo Otero +3 more
wiley +1 more source
Size‐Ramsey numbers of graphs with maximum degree three
Journal of the London Mathematical Society, Volume 111, Issue 3, March 2025.Abstract The size‐Ramsey number r̂(H)$\hat{r}(H)$ of a graph H$H$ is the smallest number of edges a (host) graph G$G$ can have, such that for any red/blue colouring of G$G$, there is a monochromatic copy of H$H$ in G$G$. Recently, Conlon, Nenadov and Trujić showed that if H$H$ is a graph on n$n$ vertices and maximum degree three, then r̂(H)=O(n8/5 ...
Nemanja Draganić, Kalina Petrova
wiley +1 more source
Upper Bounds for Linear Graph Codes
Random Structures &Algorithms, Volume 66, Issue 1, January 2025.ABSTRACT A linear graph code is a family 𝒞 of graphs on n$$ n $$ vertices with the property that the symmetric difference of the edge sets of any two graphs in 𝒞 is also the edge set of a graph in 𝒞. In this article, we investigate the maximal size of a linear graph code that does not contain a copy of a fixed graph H$$ H $$.
Leo Versteegen
wiley +1 more source
Density theorems for bipartite graphs and related Ramsey-type results
, 2007 In this paper, we present several density-type theorems which show how to find a copy of a sparse bipartite graph in a graph of positive density.
Fox, Jacob, Sudakov, Benny
core +4 more sources
Immersions of Directed Graphs in Tournaments
Random Structures &Algorithms, Volume 66, Issue 1, January 2025.ABSTRACT Recently, Draganić, Munhá Correia, Sudakov and Yuster (2022) showed that every tournament on (2+o(1))k2$$ \left(2+o(1)\right){k}^2 $$ vertices contains a 1‐subdivision of a transitive tournament on k$$ k $$ vertices, which is tight up to a constant factor. We prove a counterpart of their result for immersions.
António Girão, Robert Hancock
wiley +1 more source