Solvability and Rigidity for Topological Skew Braces

TL;DR

This paper investigates the conditions under which the solvability of the additive group in topological skew braces implies the solvability of the multiplicative group, establishing new results in the connected locally compact Hausdorff setting.

Contribution

It proves that in connected locally compact Hausdorff topological skew braces, additive solvability implies multiplicative solvability, and demonstrates the necessity of certain topological conditions.

Findings

Solvability of the additive group implies solvability of the multiplicative group in the specified setting.

Counterexamples show the importance of Hausdorff, local compactness, and connectedness assumptions.

In the compact connected abelian case, the two group laws coincide, indicating rigidity.

Abstract

We study compact and locally compact topological analogues of the Byott--Vendramin solvability problem for finite skew braces, asking whether solvability of the additive group forces solvability of the multiplicative group. Our main theorem proves an affirmative result in the connected locally compact Hausdorff setting: if \(B=(B,\cdot,\circ)\) is a connected locally compact Hausdorff topological skew brace and the additive group \((B,\cdot)\) is solvable, then the multiplicative group \((B,\circ)\) is solvable. The proof proceeds by reducing the additive group to a solvable Lie quotient and then applying an affine-action theorem: a connected Lie group acting transitively and affinely on a connected solvable Lie group, with solvable stabilizer identity component, is itself solvable. We further show that the Hausdorff, local compactness, and connectedness hypotheses are essential by constructing counterexamples when each is omitted. In the compact connected Hausdorff case with abelian additive group, we obtain a stronger rigidity phenomenon: the two group laws coincide.