✦ LIBER ✦

A counterexample to Seymour's self-minor conjecture

✍ Scribed by Bogdan Oporowski

Publisher: John Wiley and Sons
Year: 1990
Tongue: English
Weight: 212 KB
Volume: 14
Category: Article
ISSN: 0364-9024
DOI: 10.1002/jgt.3190140502

No coin nor oath required. For personal study only.

📜 SIMILAR VOLUMES

A counterexample to the bold conjecture

✍ Sakuma, Tadashi 📂 Article 📅 1997 🏛 John Wiley and Sons 🌐 English ⚖ 83 KB 👁 1 views

A pair of vertices (x, y) of a graph G is an ω-critical pair if ω(G + xy) > ω(G), where G + xy denotes the graph obtained by adding the edge xy to G and ω(H) is the clique number of H. The ω-critical pairs are never edges in G. A maximal stable set S of G is called a forced color class of G if S mee

On a Minimal Counterexample to Dade's Pr

On a Minimal Counterexample to Dade's Projective Conjecture

✍ Charles W. Eaton; Geoffrey R. Robinson 📂 Article 📅 2002 🏛 Elsevier Science 🌐 English ⚖ 96 KB

A counterexample to the rank-coloring co

A counterexample to the rank-coloring conjecture

✍ N. Alon; P. D. Seymour 📂 Article 📅 1989 🏛 John Wiley and Sons 🌐 English ⚖ 140 KB

It has been conjectured by C. van Nuffelen that the chromatic number of any graph with at least one edge does not exceed the rank of its adjacency matrix. We give a counterexample, with chromatic number 32 and with an adjacency matrix of rank 29.

A Polynomial Counterexample to the Marku

A Polynomial Counterexample to the Markus–Yamabe Conjecture

✍ Anna Cima; Arno van den Essen; Armengol Gasull; Engelbert Hubbers; Francesc Maño 📂 Article 📅 1997 🏛 Elsevier Science 🌐 English ⚖ 256 KB

We give a polynomial counterexample to both the Markus Yamabe conjecture and the discrete Markus Yamabe problem for all dimensions 3.

On possible counterexamples to Negami's

On possible counterexamples to Negami's planar cover conjecture

✍ Petr Hliněný; Robin Thomas 📂 Article 📅 2004 🏛 John Wiley and Sons 🌐 English ⚖ 281 KB

## Abstract A simple graph **__H__** is a cover of a graph **__G__** if there exists a mapping φ from **__H__** onto **__G__** such that φ maps the neighbors of every vertex υ in **__H__** bijectively to the neighbors of φ (υ) in **__G__**. Negami conjectured in 1986 that a connected graph has a fi

A Counterexample to Fulton's Conjecture

A Counterexample to Fulton's Conjecture on [formula]0, n

✍ Peter Vermeire 📂 Article 📅 2002 🏛 Elsevier Science 🌐 English ⚖ 67 KB

We describe an elementary counterexample to a conjecture of Fulton on the set of effective divisors on the space M 0 n of marked rational curves.  2002 Elsevier Science (USA)