We introduce the sphere fibration for real map germs with radial discriminant and we address the problem of its equivalence with the Milnor–Hamm tube fibration. Under natural conditions, we prove the existence of open book structures with singularities and solve the equivalence problem.
The authors acknowledge the support of USP-COFECUB Uc Ma 163-17. The third author acknowledges the support of the Labex CEMPI (ANR-11-LABX-0007-01). The first author acknowledges the Fapesp grant 2017/20455-3 and the CNPq grant 313780/2017-0.
"Milnor–Hamm sphere fibrations and the equivalence problem." J. Math. Soc. Japan 72 (3) 945 - 957, July, 2020. https://doi.org/10.2969/jmsj/82278227