The Writhing Number of a Space Curve

1971/04/01 by F. B. Fuller · 785 citations
Biochemistry, Genetics and Molecular Biology · Mathematics · #Computer science #DNA and Biological Computing #Geometry #Invariant (physics) #Mathematical physics #Mathematics #Space (punctuation)

paper · open access · doi:10.1073/pnas.68.4.815

published in Proceedings of the National Academy of Sciences 68(4), 815-819 (National Academy of Sciences)

openalex publication_date 1971/04/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/15

Abstract

A geometric invariant of a space curve, the writhing number, is defined and studied. For the central curve of a twisted cord the writhing number measures the extent to which coiling of the central curve has relieved local twisting of the cord. This study originated in response to questions that arise in the study of supercoiled double-stranded DNA rings.

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