User Tony Huynh

6 votes

"Universal" infinite graph (with respect to minors)

answered Apr 12, 2017 at 14:31

6 votes

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Does anyone know a specific polynomial-time algorithm to detect if a given signed graph contains an odd-K4 as a signed minor?

answered Apr 19, 2017 at 19:21

6 votes

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Vertex-adding number

answered Jan 9, 2017 at 11:25

6 votes

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Does the weak Hadwiger conjecture imply the Hadwiger conjecture?

answered Jan 10, 2017 at 16:18

6 votes

What upper bounds are known on the number of non-isomorphic cycle matroids?

answered Oct 12, 2017 at 12:33

6 votes

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Upper bound for chromatic number of graphs with $\omega(G)\leq\lfloor\frac{\Delta(G)+1}{2}\rfloor+1$

answered Oct 12, 2017 at 21:13

6 votes

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Minimum covers of complete graphs by $4$-cycles

answered Aug 29, 2017 at 9:18

6 votes

Good programs for drawing (weighted directed) graphs

answered Sep 5, 2017 at 13:45

6 votes

Matroids of rank two

answered Oct 11, 2017 at 12:59

6 votes

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Effect of removing an edge on Hadwiger number

answered Feb 17, 2020 at 8:44

6 votes

Accepted

Does the purported proof of Rota's conjecture provide an algorithm for calculating the forbidden minors of matroids over arbitrary finite fields?

answered Nov 5, 2020 at 13:21

6 votes

If $G$ is an infinite graph where $v_{i,j}$ is joined with $v_{k,i+j}$ for all $k,i,j$ then is the chromatic number of G always infinite?

answered Nov 8, 2020 at 22:45

6 votes

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Graph combinatorial optimization problem

answered Oct 20, 2021 at 18:14

6 votes

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Connectivity and the minimum degree of bipartite graph

answered Oct 7, 2021 at 11:11

6 votes

Distinct numbers in multiplication table

answered Jul 29, 2021 at 10:03

6 votes

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Double cover the edges of a complete graph by smaller complete graphs

answered Mar 3 at 2:56

6 votes

Book for matroid polytopes

answered Dec 12, 2023 at 20:50

6 votes

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Do longest paths in 4-connected graphs intersect?

answered Oct 9, 2023 at 14:37

6 votes

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Reference for puzzle on dividing piles and scoring products

answered Jan 7, 2015 at 13:22

6 votes

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What is the relation between size of maximum clique and branchwidth?

answered Dec 13, 2015 at 16:21

6 votes

Majority coloring for directed graphs

answered May 4, 2016 at 15:50

6 votes

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The class of $(-1,0,1)$-matrices with all row sums and column sums equal to $0$

answered May 11, 2016 at 17:11

6 votes

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Are the Gessel sequence integers composite for all $n\ge 3$?

answered Apr 15, 2016 at 15:51

6 votes

Is there a graph that is Ramsey for $P_{2n}$ but is $C_{2n+1}-$free

answered Jul 10, 2013 at 21:16

6 votes

Intersecting 4-sets

answered Nov 6, 2012 at 3:47

6 votes

Efficient Hamiltonian cycle algorithms for graph classes

answered Sep 29, 2013 at 21:16

6 votes

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Is the Manickam-Miklós-Singhi Conjecture solved?

answered Jul 19, 2014 at 18:31

6 votes

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Notation for a graph without any edges?

answered Aug 26, 2010 at 8:34

6 votes

Finding a cycle of fixed length

answered Feb 25, 2010 at 19:47

6 votes

Minor-closed classes of graphs with large numbers of excluded minors

answered Nov 28, 2011 at 6:34

Stack Exchange Network

475 Answers

"Universal" infinite graph (with respect to minors)

Does anyone know a specific polynomial-time algorithm to detect if a given signed graph contains an odd-K4 as a signed minor?

Vertex-adding number

Does the weak Hadwiger conjecture imply the Hadwiger conjecture?

What upper bounds are known on the number of non-isomorphic cycle matroids?

Upper bound for chromatic number of graphs with $\omega(G)\leq\lfloor\frac{\Delta(G)+1}{2}\rfloor+1$

Minimum covers of complete graphs by $4$-cycles

Good programs for drawing (weighted directed) graphs

Matroids of rank two

Effect of removing an edge on Hadwiger number

Does the purported proof of Rota's conjecture provide an algorithm for calculating the forbidden minors of matroids over arbitrary finite fields?

If $G$ is an infinite graph where $v_{i,j}$ is joined with $v_{k,i+j}$ for all $k,i,j$ then is the chromatic number of G always infinite?

Graph combinatorial optimization problem

Connectivity and the minimum degree of bipartite graph

Distinct numbers in multiplication table

Double cover the edges of a complete graph by smaller complete graphs

Book for matroid polytopes

Do longest paths in 4-connected graphs intersect?

Reference for puzzle on dividing piles and scoring products

What is the relation between size of maximum clique and branchwidth?

Majority coloring for directed graphs

The class of $(-1,0,1)$-matrices with all row sums and column sums equal to $0$

Are the Gessel sequence integers composite for all $n\ge 3$?

Is there a graph that is Ramsey for $P_{2n}$ but is $C_{2n+1}-$free

Intersecting 4-sets

Efficient Hamiltonian cycle algorithms for graph classes

Is the Manickam-Miklós-Singhi Conjecture solved?

Notation for a graph without any edges?

Finding a cycle of fixed length

Minor-closed classes of graphs with large numbers of excluded minors