Any smooth $n$-dimensional knot $\mathbb{S}^n\hookrightarrow\mathbb{R}^{n+2}$ is isotopic to an $n$-knot contained in the Menger $M^{n+2}_n$-continuum
Juan Pablo Díaz, Gabriela Hinojosa, Alberto Verjovsky
TL;DR
The paper addresses whether smooth $n$-knots in $\mathbb{R}^{n+2}$ can be realized within the Menger $M^{n+2}_n$-continuum. It combines the cubical-isotopy result of Boege–Hinojosa–Verjovski, which places a smooth $N^n$ into the canonical scaffolding as a cubical submanifold, with an iterative subdivision construction that produces an inverse-limit embedding of $N^n$ into $M^{n+2}_n$ while preserving isotopy. The main theorem proves that any cubical $N^n$ in the $n$-skeleton admits an isotopic copy inside $M^{n+2}_n$, which implies that every smooth knot $\mathbb{S}^n \hookrightarrow \mathbb{R}^{n+2}$ is isotopic to an $n$-knot contained in the Menger continuum. This result extends the known universality of Menger spaces from topological spaces to the smooth category up to isotopy, revealing a rich family of smooth $n$-knots within fractal continua.
Abstract
In this paper, we say that an $n$-dimensional closed submanifold $N$ embedded in $\mathbb{R}^{n+2}$ is cubical if it is contained in the $n$-skeleton of the canonical cubulation of $\mathbb{R}^{n+2}$. It has been shown by the last two authors and M. Boege that any smooth $n$-dimensional closed submanifold of $\mathbb{R}^{n+2}$ can be deformed to a cubical $ n$-manifold by a global continuous isotopy of $\mathbb{R}^{n+2}$. Here, we prove that there is an isotopic copy of $N^n$ contained in the Menger $M^{n+2}_n$-continuum. In particular, any smooth knot $\mathbb{S}^n\hookrightarrow\mathbb{R}^{n+2}$ is isotopic to a knot contained in the Menger $M^{n+2}_n$-continuum.
