Gluing Karcher-Scherk saddle towers I: Triply periodic minimal surfaces

TL;DR

This paper introduces a new method for constructing triply periodic minimal surfaces by gluing Karcher--Scherk saddle towers with phase differences, revealing a previously unnoticed vertical balancing condition.

Contribution

It extends the construction of TPMSs by incorporating phase differences, uncovering a vertical interaction condition, and broadening the known families of such surfaces.

Findings

New 5-parameter families of TPMSs

Identification of a vertical balancing condition

Expansion of known TPMSs into more general families

Abstract

We construct minimal surfaces by gluing simply periodic Karcher--Scherk saddle towers along their wings. Such constructions were previously implemented assuming a horizontal reflection plane. We break this symmetry by prescribing phase differences between the saddle towers. It turns out that, in addition to the previously known horizontal balancing condition, the saddle towers must also be balanced under a subtle vertical interaction. This interaction vanishes in the presence of a horizontal reflection plane, hence was not perceived in previous works. Our construction will be presented in a series of papers. In this first paper of the series, we will explain the background of the project and establish the graph theoretical setup that will be useful for all papers in the series. The main task of the current paper is to glue saddle towers into triply periodic minimal surfaces (TPMSs). Our construction expands many previously known TPMSs into new 5-parameter families, therefore significantly advances our knowledge on the space of TPMSs.