Lê’s conjecture

For every holomorphic map germ n:(C2,0)→(C3,0)\boldsymbol{n}:(\mathbb{C}^{2},0)\to(\mathbb{C}^{3},0) that admits an injective representative, the differential at the origin is nonzero: (dn)0≠0(d\boldsymbol{n})_{0}\neq 0. Equivalently, there is no injective holomorphic map germ n:(C2,0)→(C3,0)\boldsymbol{n}:(\mathbb{C}^{2},0)\to(\mathbb{C}^{3},0) with (dn)0=0(d\boldsymbol{n})_{0}=0.

References

Primary source

arXiv

Additional references

Progress summary

Refreshed
Claimed progress

A new paper narrows the unresolved conjecture to three cases, but none has yet been ruled out.

Lê’s conjecture concerns the structure of injective holomorphic map germs and related complex-surface singularities. Earlier literature records it as open, with only partial and conditional results.

Known results

  • The two-dimensional formulation relates injective analytic germs from (C2,0)(\mathbb{C}^{2},0) to (C3,0)(\mathbb{C}^{3},0) to smooth singular loci and constant transversal Milnor number (2006).
  • Conditional equisingularity results were obtained assuming Lê’s conjecture, with some unconditional results under additional smooth-branch hypotheses (2006).
  • A 2019 survey explicitly described the conjecture as still open and having only partial results.

October 2026 reduction

Pablo Portilla Cuadrado’s new paper is reported to reduce the remaining problem, using plane-curve singularities, cobordisms, and knot Floer bounds, to excluding orders 22, 33, and 44. This is a claimed advance, but the supplied evidence does not independently verify the reduction.

Current status (as of October 2026): Lê’s conjecture remains open; the reported reduction to orders 22, 33, and 44 is unverified, and those cases remain to be excluded.

Sources

Solutions 0

No solutions have been posted yet.