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Stable blowup for supercritical wave maps into perturbed spheres

Roland Donninger, Birgit Schörkhuber, Alexander Wittenstein

TL;DR

This work addresses stable self-similar blowup for energy-supercritical wave maps from $(1+d)$-dimensional Minkowski space into perturbed spheres $S^d_{\epsilon}$ under co-rotational symmetry. The authors reformulate the problem in similarity coordinates, construct self-similar blowup profiles by a perturbative fixed-point argument around the ground state at $\epsilon=0$, and prove nonlinear stability of these blowup solutions under small co-rotational perturbations on the full space via spectral analysis and a robust contraction mapping in an abstract Cauchy problem. The analysis relies on intersection Sobolev spaces, Schauder-type estimates with parameter dependence, and a careful treatment of the symmetry-induced unstable mode to ensure exponential decay on the stable subspace. The results extend prior stability results known for the sphere target to a class of warped-product targets close to the sphere, deepening understanding of blowup dynamics in geometric wave equations and suggesting broader robustness of self-similar blowup phenomena under scale-invariant perturbations.

Abstract

We consider wave maps from $(1+d)$-dimensional Minkowski space, $d\geq3$, into rotationally symmetric manifolds which arise from small perturbations of the sphere $\mathbb S^d$. We prove the existence of co-rotational self-similar finite time blowup solutions with smooth blowup profiles. Furthermore, we show the nonlinear asymptotic stability of these solutions under suitably small co-rotational perturbations on the full space.

Stable blowup for supercritical wave maps into perturbed spheres

TL;DR

This work addresses stable self-similar blowup for energy-supercritical wave maps from -dimensional Minkowski space into perturbed spheres under co-rotational symmetry. The authors reformulate the problem in similarity coordinates, construct self-similar blowup profiles by a perturbative fixed-point argument around the ground state at , and prove nonlinear stability of these blowup solutions under small co-rotational perturbations on the full space via spectral analysis and a robust contraction mapping in an abstract Cauchy problem. The analysis relies on intersection Sobolev spaces, Schauder-type estimates with parameter dependence, and a careful treatment of the symmetry-induced unstable mode to ensure exponential decay on the stable subspace. The results extend prior stability results known for the sphere target to a class of warped-product targets close to the sphere, deepening understanding of blowup dynamics in geometric wave equations and suggesting broader robustness of self-similar blowup phenomena under scale-invariant perturbations.

Abstract

We consider wave maps from -dimensional Minkowski space, , into rotationally symmetric manifolds which arise from small perturbations of the sphere . We prove the existence of co-rotational self-similar finite time blowup solutions with smooth blowup profiles. Furthermore, we show the nonlinear asymptotic stability of these solutions under suitably small co-rotational perturbations on the full space.

Paper Structure

This paper contains 18 sections, 28 theorems, 291 equations.

Key Result

Theorem 1.2

Let $d \geq 3$. There exists an $\epsilon^* \in \mathbb{R}$, $0 < \epsilon^* \leq \epsilon_0$ such that for every $\epsilon \in \mathbb{R}$ with $\lvert\epsilon\rvert \leq \epsilon^*$, Eq. equation for radial profile admits a self-similar solution $u_{\epsilon}^T \in C^{\infty}([0,T) \times [0,\inft such that its gradient blows up in $r=0$, i.e., The profile $f_{\epsilon}$ can be written as with

Theorems & Definitions (52)

  • Definition 1.1
  • Theorem 1.2
  • Theorem 1.3
  • Remark 1.4
  • Remark 1.5
  • Theorem 1.6
  • Lemma 2.1
  • Corollary 2.2
  • Lemma 2.3
  • Lemma 2.4
  • ...and 42 more