Topology

Outer reloid of direct product of filters ★★

Author(s): Porton

Question   $ ( \mathsf{\tmop{RLD}})_{\tmop{out}} ( \mathcal{A} \times^{\mathsf{\tmop{FCD}}} \mathcal{B}) = \mathcal{A} \times^{\mathsf{\tmop{RLD}}} \mathcal{B} $ for every f.o. $ \mathcal{A} $, $ \mathcal{B} $?

Keywords: direct product of filters; outer reloid

Posted by porton
updated September 4th, 2010
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Topology

The 4x5 chessboard complex is the complement of a link, which link? ★★

Author(s): David Eppstein

Problem   Ian Agol and Matthias Goerner observed that the 4x5 chessboard complex is the complement of many distinct links in the 3-sphere. Their observation is non-constructive, as it uses the resolution of the Poincare Conjecture. Find specific links that have the 4x5 chessboard complex as their complement.

Keywords: knot theory, links, chessboard complex

Posted by rybu
updated September 4th, 2010
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Graph Theory » Basic G.T. » Cycles

Strong 5-cycle double cover conjecture ★★★

Author(s): Arthur; Hoffmann-Ostenhof

Conjecture   Let $ C $ be a circuit in a bridgeless cubic graph $ G $. Then there is a five cycle double cover of $ G $ such that $ C $ is a subgraph of one of these five cycles.

Keywords: cycle cover

Posted by arthur
updated November 24th, 2011
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