Constant mean curvature surfaces in the sub-Lorentzian Heisenberg group

Samuël Borza; Andrea Pinamonti; Omar Zoghlami

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arXiv · 2605.31397

Constant mean curvature surfaces in the sub-Lorentzian Heisenberg group

Samuël Borza·Andrea Pinamonti·Omar Zoghlami

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Abstract

We study constant horizontal mean curvature surfaces in the sub-Lorentzian Heisenberg group. We derive the first-variation formula for horizontal area under volume-preserving radial variations and show that smooth isoperimetric candidates have constant horizontal mean curvature away from the characteristic set. We then give a complete classification of smooth boost-symmetric constant mean curvature surfaces: their characteristic sets, causal behaviour, and ambient sub-Lorentzian isometry classes. From this classification, we single out a family of smooth, acausal, boost-symmetric surfaces with nonzero constant mean curvature. Written as a two-sheeted graph over the exterior of a future hyperbola, this family is a natural sub-Lorentzian analogue of the Pansu bubbles and leads us to conjecture that it gives the isoperimetric maximisers in the sub-Lorentzian Heisenberg group.

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BibTeX RIS

Samuël Borza, Andrea Pinamonti, Omar Zoghlami. 2026-05-29. Constant mean curvature surfaces in the sub-Lorentzian Heisenberg group. https://arxiv.org/abs/2605.31397

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