The isometry degree of a computable copy of $\ell^p$
Timothy H. McNicholl, D. M. Stull · arXiv (Cornell University) · 2016
When $p$ is a computable real so that $p \geq 1$, the isometry degree of a computable copy $\mathcal{B}$ of $\ell^p$ is defined to be the least powerful Turing degree that computes a linear isometry of $\ell^p$ onto $\mathcal{B}$. We show that this degree always exists and that when $p eq 2$ these degrees are precisely the c.e. degrees.