Existence of a stable shrinker for the corotational harmonic map heat flow in higher space dimensions

We study singularity formation for the heat flow of harmonic maps from $\R^d$ into $\mathbb{S}^d$ in supercritical dimensions $d \in \{3,4,5,6\}$.

It is well known that in each of these dimensions there exist infinitely many self-similar solutions that provide examples of loss of regularity in finite time.

In this paper, we extend the results of \cite{BieDon18}, \cite{BieDonSch17} for $d=3$ to higher space dimensions $d \in \{4,5,6\}$ and prove the existence of a monotonically increasing self-similar profile $f_0$, which is asymptotically stable under small corotational perturbations.

To construct the solution and resolve the spectral problem, we use rigorous computer assistance.

As a byproduct of our stability analysis, we also obtain finite-codimension stability of arbitrary self-similar profiles within the corotational class.