Combinatorics
Provisional editorial order for Top Open Problems: Millennium Prize Problems first, followed by assessed difficulty tiers; the unassessed remainder keeps its previous catalogue order. About rankings
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- Math-1877 Exact matching in red-blue bipartite graphs
- Math-1878 Generic global rigidity in three dimensions
- Math-1879 Generic rigidity in three dimensions
- Math-1880 Goddyn's conjecture on thin spanning trees
- Math-1881 Gonality and edge subdivisions
- Math-1882 Head-disjoint strongly connected orientations
- Math-1883 Incomplete splitting-off in digraphs
- Math-1884 Independent arborescences in acyclic digraphs
- Math-1885 Independent trees
- Math-1886 Integer decomposition of smooth polytopes
- Math-1887 List colouring of two matroids
- Math-1888 Local edge-connectivity augmentation of a hypergraph with fixed rank
- Math-1889 Maximum square-free 2-matching
- Math-1890 Maximum weight bounded fractional matching
- Math-1891 Maximum weight k-element subsets of perfect matchings
- Math-1892 Min-sum two edge-disjoint paths
- Math-1893 Opposite vertices of base polyhedra
- Math-1894 Orientation with shortest round trip
- Math-1895 Parity constrained strongly connected orientations
- Math-1896 Partition median problem
- Math-1897 Partitioning a bipartite graph into proportional factors
- Math-1898 Rainbow matchings in bipartite graphs
- Math-1899 Rota's conjecture on disjoint bases
- Math-1900 Scrambled Rota conjecture
- Math-1901 Serial symmetric exchanges
- Math-1902 Strong colouring of matroid-graph pairs
- Math-1903 Upper bound on common independent set cover
- Math-1904 Weighted bipartite edge colouring
- Math-2074 Acyclic orientation with parity constraints
- Math-2075 Edge-covering number of 2-polymatroids
- Math-2076 Finding kernels in special digraphs
- Math-2077 Highly element-connected orientation
- Math-2078 Infinite Lucchesi-Younger
- Math-2079 Maximum weakly stable matchings in graphs without odd preference cycles
- Math-2080 Orientation of nonideal clutters
- Math-2081 Orientation-compatible w-vertex cover
- Math-2082 Polyhedral description of kernels
- Math-2083 Recognition of Seymour graphs
- Math-2084 S-T edge-connectivity augmentation
- Math-2085 Suppose a geometric graph has no pairwise k-crossing lines
- Math-2086 Suppose H is a linear 3-uniform hypergraph, i
- Math-2087 Does every thrackle have average degree at most 2
- Math-2088 What is the minimum number of n-simplexes needed to triangulate the n-cube
- Math-2089 The "cycle double cover conjecture" states that every bridgeless graph contains a set of cycles which cover each edge of
- Math-2090 "Seymour's Second Neighborhood Conjecture" Any oriented graph has a vertex whose outdegree is at most its second outdegr
- Math-2091 Suppose that G is a tree
- Math-2092 A graph G is said to be uniquely H-saturated if it contains no H, but adding any edge to G creates exactly one copy of H
- Math-2093 Given a permutation σ, what is the maximum number of copies of σ that a permutation on n symbols may contain
- Math-2094 Given two permutations σ and τ, what is the expected number of copies of σ in a permutation chosen uniformly at random f
- Math-2095 Show that the inversion permutation, i