Displaying similar documents to “On the vertex connectivity of a relation in an association scheme.”

Highly connected counterexamples to a conjecture on α-domination

Zsolt Tuza (2005)

Discussiones Mathematicae Graph Theory


An infinite class of counterexamples is given to a conjecture of Dahme et al. [1] concerning the minimum size of a dominating vertex set that contains at least a prescribed proportion of the neighbors of each vertex not belonging to the set.

An update on a few permanent conjectures

Fuzhen Zhang (2016)

Special Matrices


We review and update on a few conjectures concerning matrix permanent that are easily stated, understood, and accessible to general math audience. They are: Soules permanent-on-top conjecture†, Lieb permanent dominance conjecture, Bapat and Sunder conjecture† on Hadamard product and diagonal entries, Chollet conjecture on Hadamard product, Marcus conjecture on permanent of permanents, and several other conjectures. Some of these conjectures are recently settled; some are still open.We...

On the Collatz conjecture

Sebastian Hebda (2013)

Colloquium Mathematicae


We propose two conjectures which imply the Collatz conjecture. We give a numerical evidence for the second conjecture.