Ishikawa's classification conjecture for stable proper frontal map germs

Let f ⁣:(Cn,0)(Cn+1,0)f\colon (\mathbb{C}^n,0)\to(\mathbb{C}^{n+1},0) be a stable proper frontal map germ of corank 11, with Legendrian lift f~\tilde f. Define Ishikawa's indices by

i=dimf~O2n+1fmn+1{2,,n},j+1=dimOnf~m2n+1{1,,n2}.i=\dim\frac{\tilde f^*\mathscr{O}_{2n+1}}{f^*\mathfrak{m}_{n+1}}\in\{2,\dots,n\},\qquad j+1=\dim\frac{\mathscr{O}_n}{\tilde f^*\mathfrak{m}_{2n+1}}\in\left\{1,\dots,\left\lfloor\frac{n}{2}\right\rfloor\right\}.

Here square brackets in the source denote the floor function. Ishikawa's classification conjecture. The stable proper frontal map germs are given by Ishikawa's Ai,jA_{i,j} singularities with these index ranges, and all stable frontal multigerms are obtained by transverse self-intersections of these mono-germs. The paper presents this statement as a theorem and supplies the classification in the cited theorem, so it is resolved rather than an open conjecture.

Sources & referencesView supporting material

Primary source

C. Muñoz-Cabello, J. J. Nuño-Ballesteros and R. Oset Sinha, “Deformations of corank 1 frontals”, arXiv:2302.13621 (2023).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.