Equisingularity of families of functions on isolated determinantal singularities

Rafaela S. Carvalho, Juan J. Nuño-Ballesteros, Bruna Oréfice-Okamoto, João N. Tomazella

Published 2020-05-09Version 1

We study the equisingularity of a family of function germs $\{f_t\colon(X_t,0)\to (\mathbb{C},0)\}$, where $(X_t,0)$ are $d$-dimensional isolated determinantal singularities. We define the $(d-1)$th polar multiplicity of the fibers $X_t\cap f_t^{-1}(0)$ and we show how the constancy of the polar multiplicities is related to the constancy of the Milnor number of $f_t$ and the Whitney equisingularity of the family.