Novel Idea on Edge-Ultrafilter and Edge-Tangle

Takaaki Fujita *

Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-Cho, Kiryu Gunma 376-8515, Japan.

*Author to whom correspondence should be addressed.


The study of width parameters holds significant interest in both graph theory and algebraic settings. Among these, the tree-cut decomposition stands out as a key metric. The "Edge-tangle" concept is closely related to the "tree-cut width" width parameter in graph theory. This obstruction is often seen as vital for creating effective algorithms to calculate graph width, with the edge-tangle being the specific obstruction for tree-cut width. Meanwhile, the idea of an "Ultrafilter" is well-established in topology and algebra.  Due to their versatile nature, ultrafilters hold significant and broad-ranging importance. In this paper, we introduce a new concept called Edge-Ultrafilters for graphs and demonstrate how they are equivalent to Edge-tangles.

Keywords: Filter, ultrafilter, tangle, edge-tangle, tree-cut-width, tree-cut-decomposition

How to Cite

Fujita, T. (2024). Novel Idea on Edge-Ultrafilter and Edge-Tangle. Asian Research Journal of Mathematics, 20(4), 18–22.


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