Let $X^n$ be an Alexandrov space, and $f: X^n\to \mathbb R^n$ a regular map, does the level set necessary be an Alexandrov space?
In my mind, the intrinsic metric on the level set is 'comparable' to the ambient metric.
Let $X^n$ be an Alexandrov space, and $f: X^n\to \mathbb R^n$ a regular map, does the level set necessary be an Alexandrov space?
In my mind, the intrinsic metric on the level set is 'comparable' to the ambient metric.