37 problems
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Merino–Welsh conjecture for bridgeless loopless connected graphs
Merino–Welsh conjecture. Every such graph satisfies
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Boesch's conjecture on uniformly most reliable graphs
Boesch's conjecture. Each uniformly most reliable graph in is a -element in .
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The Merino–Welsh inequality for composition enumerators
Let be the composition-indexed quantity used in the source. Let be a composition with and . Merino–Welsh co…
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The multiplicative Merino–Welsh conjecture for matroids
Let be a matroid with no loops or isthmuses, and let denote its Tutte polynomial. Multiplicative Merino–Welsh conjecture. … This is presented as a seemingly stronger…
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Stanley's -vector conjecture for matroids
Stanley's -vector conjecture. For any matroid , there exists such a set of monomials.
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Conjecture that the critical group is not determined by the Tutte polynomial
For a connected undirected graph , let denote its Tutte polynomial and let denote its critical group. Non-determination conjecture. There exist conn…
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Shteiner–Shteyner's degree-sequence conjecture for bipartite graphs
Shteiner–Shteyner's conjecture. If is bipartite, then
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The cubic graph relation between Speyer and Tutte polynomials
Cubic Tutte relation conjecture. The second derivative of Speyer's polynomial satisfies
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Tutte-polynomial inequality for simple co-simple matroids
Let be a matroid. A matroid is simple if it has no loops or parallel elements, and co-simple if its dual has no loops or parallel elements. Simple co-simple matroid conjecture.…
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A ring-level lift of the universal Tutte–Grothendieck invariant
The universal Tutte–Grothendieck invariant is a morphism of abelian groups … The map of -theory spectra lift…
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Regular complete multipartite graph conjecture for Tutte-maximum graphs
Let denote the class of graphs with vertices and edges, and order this class by the Tutte polynomial poset. A graph is Tutte-maximum if it is a maximum…
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Wang–Liu–Shao maximum graph conjecture for the Tutte polynomial poset
Let be the class of graphs with vertices and edges, equipped with its Tutte polynomial poset, and consider the graphs described by Wang and by Liu a…
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Welsh–Merino spanning-tree orientation conjecture
Let be a graph. Consider its number of spanning trees, its number of acyclic orientations, and its number of totally cyclic orientations. Welsh–Merino conjecture. The number of…
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Welsh's FPRAS conjecture for Tutte polynomials of dense graphs
For , let be the class of -dense graphs satisfying . An FPRAS for a function is a randomized algorithm th…
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Conde–Merino–Welsh conjecture for the Tutte polynomial
Conde–Merino–Welsh conjecture. The following inequalities hold:
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Las Vergnas's second Tutte polynomial conjecture for binary matroids
Let be a binary matroid, let denote its Tutte polynomial, and let be an integer. Las Vergnas's second conjecture. The value … is an odd integer for every binary…
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Relationship between lattice-point and algebro-geometric formulas for the Tutte polynomial
Conjectured relationship. There is a relationship between this formula for the Tutte polynomial and the algebro-geometric formula for the Tutte polynomial. The conjecture proposes…
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Jackson–Sokal's density conjecture for Tutte-polynomial zeros
Jackson–Sokal's density conjecture. The zeros of the Tutte polynomials of graphs are dense in the following regions: (a) and ; (b) and ; (c)…
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Jackson–Sokal's limiting-region conjecture for Tutte-polynomial zeros
Let be the inclusion-wise increasing sequence of regions in the plane associated with the Jackson–Sokal hierarchy, and let denote a limiting region. J…
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Jackson–Sokal's hierarchy conjecture for Tutte-polynomial zero-free regions
Let be a graph, and let be the zero-free region in the plane. A graph is 2-connected if it is connected and has no cut vertex. Jackson–Sokal's hierarchy conjectur…
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A relationship between lattice-point and algebro-geometric formulas for the Tutte polynomial
Relationship conjecture. There is a relationship between the lattice-point-counting formula for the Tutte polynomial developed here and Speyer's algebro-geometric formula for the T…
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The matroidal Merino–Welsh conjectures
Let be a matroid without loops or coloops, and let be its Tutte polynomial. Matroidal Merino–Welsh conjectures. The following inequalities hold: … … and … These conj…
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The graphic Merino–Welsh conjectures
Let be a graph with no bridges and no loops. Let be its number of spanning trees, let be its number of acyclic orientations, and let be its number of to…
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Subparking-function and acyclic-cut orientation conjecture for graph Tutte polynomials
Subparking-function and acyclic-cut orientation conjecture. For any graph and choice of sink , there exists an ordered, -rooted spanning tree of such that
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Biggs's Tutte-polynomial conjecture for undirected graphs
Biggs's conjecture. The Biggs–Merino polynomial is equal to