On Unavoidable Induced Subgraphs in Large Prime Graphs
نویسنده
چکیده
Chudnovsky, Kim, Oum, and Seymour recently established that any prime graph contains one of a short list of induced prime subgraphs [1]. In the present paper we reprove their theorem using many of the same ideas, but with the key model-theoretic ingredient of first determining the so-called amount of stability of the graph. This approach changes the applicable Ramsey theorem, improves the bounds and offers a different structural perspective on the graphs in question. Complementing this, we give an infinitary proof which implies the finite result.
منابع مشابه
Computing Maximum Unavoidable Subgraphs Using SAT Solvers
Unavoidable subgraphs have been widely studied in the context of Ramsey Theory. The research in this area focuses on highly structured graphs such as cliques, cycles, paths, stars, trees, and wheels. We propose to study maximum unavoidable subgraphs measuring the size in the number of edges. We computed maximum unavoidable subgraphs for graphs up to order nine via SAT solving and observed that ...
متن کاملUnavoidable induced subgraphs in large graphs with no homogeneous sets
An n-vertex graph is prime if it has no homogeneous set, that is a set X of vertices (2 ≤ |X| ≤ n − 1) such that every vertex not in X is either complete or anticomplete to X. A chain of length t is a sequence of t+ 1 vertices such that for every vertex in the sequence except the first one, its immediate predecessor is its unique neighbor or its unique non-neighbor among all of its predecessors...
متن کاملUnavoidable subgraphs of colored graphs
A natural generalization of graph Ramsey theory is the study of unavoidable subgraphs in large colored graphs. In this paper, we find a minimal family of unavoidable graphs in two-edgecolored graphs. Namely, for a positive even integer k, let Sk be the family of two-edge-colored graphs on k vertices such that one of the colors forms either two disjoint Kk/2s or simply one Kk/2. Bollobás conject...
متن کاملDeciding whether there are infinitely many prime graphs with forbidden induced subgraphs
7 A homogeneous set of a graph G is a set X of vertices such that 2 ≤ |X| < |V (G)| 8 and no vertex in V (G) − X has both a neighbor and a non-neighbor in X. A graph 9 is prime if it has no homogeneous set. We present an algorithm to decide whether a 10 class of graphs given by a finite set of forbidden induced subgraphs contains infinitely 11 many non-isomorphic prime graphs. 12
متن کاملOn subgraphs of Cartesian product graphs and S-primeness
In this paper we consider S-prime graphs, that is the graphs that cannot be represented as nontrivial subgraphs of nontrivial Cartesian products of graphs. Lamprey and Barnes characterized S-prime graphs via so-called basic S-prime graphs that form a subclass of all S-prime graphs. However, the structure of basic S-prime graphs was not known very well. In this paper we prove several characteriz...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2015