Problems / geometry-topology
geometry-topology / Singularity theory; Milnor fibres and contact loci
The Budur-Fernandez de Bobadilla-Le-Nguyen conjecture on initial-form Milnor fibres of topologically equivalent germs
With f1,f2 the Zariski counterexample germs, f~j=fj(z)+t2 on CN+1 are topologically right equivalent with isolated critical points, but H0((f~1)∗−1(1);Z)≅Z while H0((f~2)∗−1(1);Z)≅Z2: one initial-form Milnor fibre is connected and the other has two components. This disproves both the embedded and the right-equivalence formulations. It says nothing about weaker invariants the conjecture was meant to capture, such as cohomology of contact loci.