Zobrazeno 1 - 10
of 74
pro vyhledávání: '"Vena, Lluís"'
Autor:
Serra, Oriol, Vena, Lluís
In \cite[Serra, Vena, Extremal families for the Kruskal-Katona theorem]{sv21}, the authors have shown a characterization of the extremal families for the Kruskal-Katona Theorem. We further develop some of the arguments given in \cite{sv21} and give a
Externí odkaz:
http://arxiv.org/abs/2305.10152
We extend the notion of graph homomorphism to cellularly embedded graphs (maps) by designing operations on vertices and edges that respect the surface topology; we thus obtain the first definition of map homomorphism that preserves both the combinato
Externí odkaz:
http://arxiv.org/abs/2305.03107
Autor:
Serra, Oriol, Vena, Lluís
Given a family $S$ of $k$--subsets of $[n]$, its lower shadow $\Delta(S)$ is the family of $(k-1)$--subsets which are contained in at least one set in $S$. The celebrated Kruskal--Katona theorem gives the minimum cardinality of $\Delta(S)$ in terms o
Externí odkaz:
http://arxiv.org/abs/2304.05145
Autor:
Balko, Martin, Chodounský, David, Dobrinen, Natasha, Hubička, Jan, Konečný, Matěj, Vena, Lluis, Zucker, Andy
As a result of 33 intercontinental Zoom calls, we characterise big Ramsey degrees of the generic partial order. This is an infinitary extension of the well known fact that finite partial orders endowed with linear extensions form a Ramsey class (this
Externí odkaz:
http://arxiv.org/abs/2303.10088
Publikováno v:
Algebraic Combinatorics, Volume 5 (2022) no. 6, pp. 1337-1351
We prove that the ribbon graph polynomial of a graph embedded in an orientable surface is irreducible if and only if the embedded graph is neither the disjoint union nor the join of embedded graphs. This result is analogous to the fact that the Tutte
Externí odkaz:
http://arxiv.org/abs/2212.10920
Autor:
Balko, Martin, Chodounský, David, Dobrinen, Natasha, Hubička, Jan, Konečný, Matěj, Vena, Lluis, Zucker, Andy
We characterize the big Ramsey degrees of free amalgamation classes in finite binary languages defined by finitely many forbidden irreducible substructures, thus refining the recent upper bounds given by Zucker. Using this characterization, we show t
Externí odkaz:
http://arxiv.org/abs/2110.08409
Publikováno v:
In European Journal of Combinatorics May 2024 118
Autor:
Balko, Martin, Chodounský, David, Hubička, Jan, Konečný, Matěj, Nešetřil, Jaroslav, Vena, Lluís
Using the Carlson-Simpson theorem, we give a new general condition for a structure in a finite binary relational language to have finite big Ramsey degrees
Comment: 6 pages, extended abstract accepted to EUROCOMB 2021
Comment: 6 pages, extended abstract accepted to EUROCOMB 2021
Externí odkaz:
http://arxiv.org/abs/2105.12184
Autor:
Balko, Martin, Chodounský, David, Dobrinen, Natasha, Hubička, Jan, Konečný, Matěj, Vena, Lluis, Zucker, Andy
As a result of 33 intercontinental Zoom calls, we characterise big Ramsey degrees of the generic partial order in a similar way as Devlin characterised big Ramsey degrees of the generic linear order (the order of rationals).
Comment: 6 pages, ex
Comment: 6 pages, ex
Externí odkaz:
http://arxiv.org/abs/2105.10542
We prove that the universal homogeneous 3-uniform hypergraph has finite big Ramsey degrees. This is the first case where big Ramsey degrees are known to be finite for structures in a non-binary language. Our proof is based on the vector (or product)
Externí odkaz:
http://arxiv.org/abs/2008.00268