Triply Orthogonal Line Congruences with Common Middle Surface
Journal for geometry and graphics, Tome 14 (2010) no. 1, pp. 45-58
Cet article a éte moissonné depuis la source Heldermann Verlag
Let S be a non parabolic line congruence in E3, whose middle surface P(u,v) is different from its middle envelope M(u,v). We prove that there exist two line congruences S', S'' orthogonal to S and to each other with common middle surface P(u,v) iff S is isotropic or the straight lines of S', S'' are directed by the tangent vectors of the spherical image of the S-principal ruled surfaces of S, in case S is not isotropic. Then, studying the properties of a triplet S, S', S'', we find a new geometric interpretation for the curvature of S.
Classification :
53A25
Mots-clés : Orthogonal line congruences, middle surface, middle envelope, curvature of a line congruence
Mots-clés : Orthogonal line congruences, middle surface, middle envelope, curvature of a line congruence
@article{JGG_2010_14_1_JGG_2010_14_1_a3,
author = {D. Papadopoulou and P. Koltsaki },
title = {Triply {Orthogonal} {Line} {Congruences} with {Common} {Middle} {Surface}},
journal = {Journal for geometry and graphics},
pages = {45--58},
year = {2010},
volume = {14},
number = {1},
url = {http://geodesic.mathdoc.fr/item/JGG_2010_14_1_JGG_2010_14_1_a3/}
}
TY - JOUR AU - D. Papadopoulou AU - P. Koltsaki TI - Triply Orthogonal Line Congruences with Common Middle Surface JO - Journal for geometry and graphics PY - 2010 SP - 45 EP - 58 VL - 14 IS - 1 UR - http://geodesic.mathdoc.fr/item/JGG_2010_14_1_JGG_2010_14_1_a3/ ID - JGG_2010_14_1_JGG_2010_14_1_a3 ER -
D. Papadopoulou; P. Koltsaki . Triply Orthogonal Line Congruences with Common Middle Surface. Journal for geometry and graphics, Tome 14 (2010) no. 1, pp. 45-58. http://geodesic.mathdoc.fr/item/JGG_2010_14_1_JGG_2010_14_1_a3/