Problems / theoretical-computer-science
theoretical-computer-science / Fine-grained complexity; graph algorithms
The APSP hypothesis: are all-pairs shortest paths computable in truly subcubic time?
Yes: deterministic O(n2.9995) algorithms for APSP and for the (min,+)-product with polynomially bounded integer weights on the word RAM (the Lean development states n2.99942), and Exact Triangle in O(n2.9983), refuting the APSP and Exact Triangle hypotheses; a Las Vegas O(n2.998) version works for real weights. The core is a new thin-matrix-product algorithm solving Lopsided All-Edges Sparse Triangle, with known reductions giving the rest. The same paper refutes the 3SUM hypothesis, catalogued separately. The constants are enormous; the impact is on the theory of subcubic equivalences, not on practice. SETH and Orthogonal Vectors are unaffected.