Open Problems

Title	Author(s)	Imp.¹	Rec.²	Area » Topic » Subtopic	Posted by
Subgraph of large average degree and large girth.	Thomassen	✭✭	0	Graph Theory » Basic G.T.	fhavet
Edge-disjoint Hamilton cycles in highly strongly connected tournaments.	Thomassen	✭✭	0	Graph Theory » Directed Graphs » Tournaments	fhavet
Partitionning a tournament into k-strongly connected subtournaments.	Thomassen	✭✭	0	Graph Theory » Directed Graphs » Tournaments	fhavet
Inscribed Square Problem	Toeplitz	✭✭	0	Topology	dlh12
The Crossing Number of the Complete Bipartite Graph	Turan	✭✭✭	0	Graph Theory » Topological G.T. » Crossing numbers	Robert Samal
Turán's problem for hypergraphs	Turan	✭✭	0	Graph Theory » Hypergraphs	fhavet
5-flow conjecture	Tutte	✭✭✭✭	0	Graph Theory » Coloring » Nowhere-zero flows	mdevos
4-flow conjecture	Tutte	✭✭✭	0	Graph Theory » Coloring » Nowhere-zero flows	mdevos
3-flow conjecture	Tutte	✭✭✭	0	Graph Theory » Coloring » Nowhere-zero flows	mdevos
Triangle-packing vs triangle edge-transversal.	Tuza	✭✭	0	Graph Theory » Extremal G.T.	fhavet
Dense rational distance sets in the plane	Ulam	✭✭✭	0	Geometry	mdevos
Colouring the square of a planar graph	Wegner	✭✭	0	Graph Theory » Coloring » Vertex coloring	fhavet
Real roots of the flow polynomial	Welsh	✭✭	0	Graph Theory » Coloring » Nowhere-zero flows	mdevos
Number of Cliques in Minor-Closed Classes	Wood	✭✭	0	Graph Theory	David Wood
Point sets with no empty pentagon	Wood	✭	1	Geometry	David Wood
Generalised Empty Hexagon Conjecture	Wood	✭✭	1	Geometry	David Wood
Woodall's Conjecture	Woodall	✭✭✭	0	Graph Theory » Directed Graphs	mdevos
Minimum number of arc-disjoint transitive subtournaments of order 3 in a tournament	Yuster	✭✭	0	Graph Theory	fhavet
Extremal problem on the number of tree endomorphism	Zhicong Lin	✭✭	1	Graph Theory » Extremal G.T.	shudeshijie
Bounding the on-line choice number in terms of the choice number	Zhu	✭✭	1	Graph Theory » Coloring » Vertex coloring	Jon Noel

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