Equivalence of the strengthened Hanna Neumann conjecture and the amalgamated graph conjecture

@article{Dicks1994EquivalenceOT,
  title={Equivalence of the strengthened Hanna Neumann conjecture and the amalgamated graph conjecture},
  author={Warren Dicks},
  journal={Inventiones mathematicae},
  year={1994},
  volume={117},
  pages={373-389}
}
  • Warren Dicks
  • Published 1 December 1994
  • Mathematics
  • Inventiones mathematicae
SummaryWe show that Walter Neumann's strengthened form of Hanna Neumann's conjecture on the best possible upper bound for the rank of the intersection of two subgroups of a free group is equivalent to a conjecture on the best possible upper bound for the number of edges in a bipartite graph with a certain weak symmetry condition. We illustrate the usefulness of this equivalence by deriving relatively easily certain previously known results. 
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References

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