Is there a metric space on $\omega^\omega$ such that $\alpha+n\to\alpha+\omega$ as $n\to\infty$?
Let $\omega^\omega$ be the set of all ordinals less than $\omega^\omega$ then I seek a function:
$d:\omega^\omega\times\omega^\omega\to\Bbb R$ such that $\omega^\omega,d$ is a metric space
and for all $\alpha\in\omega^\omega$, adding further integers converges to $\alpha+\omega$
I'm aware of the Order Topology but this looks to be far from a metric space.
Let $\alpha$ be any countably infinite ordinal. Fix a bijection $\varphi:\alpha\to\omega$ and define
$$f:\alpha\to\Bbb R:\eta\mapsto\sum_{\xi<\eta}2^{-\varphi(\xi)}\;;$$
then $f$ is an order-embedding of $\alpha$ in $\Bbb R$. If $\alpha$ has the order topology, $f$ is a homeomorphism of $\alpha$ onto $f[\alpha]$, and you can use it to define a metric on $\alpha$.