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Surface nematic uniformity

delete2026-01-30
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PRE
AI
P
Pedrini, Andrea
E
Epifanio G. Virga *
DOI:10.1103/xpvv-zv23delete
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Abstract

Abstract

En 中文
An antlike observer confined to a two-dimensional surface traversed by stripes would wonder whether such a striped landscape could be devised in such a way as to appear to be the same wherever they go. Differently stated, this is the problem studied in this paper. In a more technical jargon, we determine all possible uniform nematic fields on a smooth surface. It was already known that for such a field to exist, the surface must have constant negative Gaussian curvature. Here we show that all uniform nematic fields on such a surface are parallel transported (in Levi-Civita's sense) by special systems of geodesics, which are termed uniform. We prove that, for every geodesic on the surface, there are two systems of uniform geodesics that include it; they are conventionally called right and left, to evoke handedness. We found explicitly all uniform fields for Beltrami's pseudosphere. Since both geodesics and uniformity are preserved under isometries, by a classical theorem of Minding, the solution for the pseudosphere carries over all other admissible surfaces, thus providing a general solution to the problem (at least in principle). The proved existence of surface nematic uniform fields suggests the definition of a generalized intrinsic elastic energy for fluid membranes with nematic order, which is but one of the many possible applications of our geometric result.
Keywords:
ORIENTATIONAL ORDER
MEMBRANES

Journal

Physical Review E cover
Physical Review E
IF:
2.4
Papers:
1.3K
Citations:
10.2W

Organization

U
university of pavia
Scholars:
2.1W
Papers: 1.6W
Citations: 8