{ "id": "2308.05284", "version": "v1", "published": "2023-08-10T02:01:33.000Z", "updated": "2023-08-10T02:01:33.000Z", "title": "On invariants of a map germ from n-space to 2n-space", "authors": [ "Juan José Nuño-Ballesteros", "Otoniel Nogueira da Silva", "João Nivaldo Tomazella" ], "categories": [ "math.AG", "math.CV" ], "abstract": "We consider $\\mathcal{A}$-finite map germs $f$ from $(\\mathbb{C}^n,0)$ to $(\\mathbb{C}^{2n},0)$. First, we show that the number of double points that appears in a stabilization of $f$, denoted by $d(f)$, can be calculated as the length of the local ring of the double point set $D^2(f)$ of $f$, given by the Mond's ideal. In the case where $n\\leq 3$ and $f$ is quasihomogeneous, we also present a formula to calculate $d(f)$ in terms of the weights and degrees of $f$. Finally, we consider an unfolding $F(x,t) = (f_t(x),t)$ of $f$ and we find a set of invariants whose constancy in the family $f_t$ is equivalent to the Whitney equisingularity of $F$. As an application, we present a formula to calculate the Euler obstruction of the image of $f$.", "revisions": [ { "version": "v1", "updated": "2023-08-10T02:01:33.000Z" } ], "analyses": { "keywords": [ "invariants", "finite map germs", "whitney equisingularity", "monds ideal", "euler obstruction" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }