Killing-form convergence conjecture for Hermitian curvature flow on complex simple groups

From papers

Let GG be a complex Lie group whose Lie algebra is the complexification g=gRC\mathfrak g=\mathfrak g_{\mathbb R}\otimes\mathbb C of a simple compact real Lie algebra gR\mathfrak g_{\mathbb R} with invariant metric  \langle\,\ \rangle. Let κSym1,1(g)\kappa\in\operatorname{Sym}^{1,1}(\mathfrak g) correspond to  1Sym2(gR)\langle\,\ \rangle^{-1}\in\operatorname{Sym}^{2}(\mathfrak g_{\mathbb R}); this element is called the Killing form. Let h(t)h(t) solve the Hermitian curvature flow ODE on its maximal time interval [0,tmax)[0,t_{\max}). Killing-form convergence conjecture. There exist gGg\in G and λR\lambda\in\mathbb R such that h(t)h(t) pinches towards λAdg(κ)\lambda\operatorname{Ad}_g(\kappa), namely

h(t)h(t)λAdg(κ),ttmax.\frac{h(t)}{|h(t)|_{\infty}}\to\lambda\operatorname{Ad}_g(\kappa),\qquad t\to t_{\max}.

The conjecture describes the expected asymptotic behavior of the reduced Hermitian curvature flow on complex Lie groups with simple compact real form: after normalization, the solution should converge to a translate and scalar multiple of the Killing form. The supplied text gives no resolution, so its status remains open.

Progress summary

Solved

A 2021 paper disproved the conjecture for the groups corresponding to three or more dimensions, while the smallest case is known to converge.

The conjecture, stated in 2017, predicts normalized convergence of Hermitian curvature flow on complex simple groups to a translated and rescaled Killing form.

Known results

  • For G=SL2(C)G=\operatorname{SL}_2(\mathbb{C}), the normalized solution converges to the dual of the Killing form (2017).
  • The metric induced by κ\kappa is scale-static under the flow (2017).

December 2021 counterexample

A proved counterexample shows that the canonical Killing-form metric is dynamically unstable on SLn(C)\operatorname{SL}_n(\mathbb{C}) for n3n\ge 3. Solutions arbitrarily close to it can have finite-time rescaled limits locally modeled on shrinking solitons on SLn1(C)H2n1(C)\operatorname{SL}_{n-1}(\mathbb{C})\ltimes H_{2n-1}(\mathbb{C}), contradicting universal convergence to the canonical metric.

Current status (as of August 2026): The general convergence conjecture is disproved for SLn(C)\operatorname{SL}_n(\mathbb{C}) with n3n\ge 3, while the SL2(C)\operatorname{SL}_2(\mathbb{C}) case is known positively.

Sources
Sources & referencesView supporting material

Primary source

Yury Ustinovskiy, “Hermitian curvature flow on complex homogeneous manifolds”, arXiv:1706.07023 (2017).

Solutions 0

No solutions have been posted yet.