sigmatrooppiset

I’m not finding reliable sources for the term "sigmatrooppiset." Could you specify the context or domain you have in mind (for example mathematics, linguistics, biology, culture, or a fictional concept)? If you provide a definition or more details, I can generate a concise, neutral wiki-style article under 300 words in plain text. If you’d like, I can also draft a neutral stub outline now and fill it in once the term is clarified.