2024-03-28T11:59:06Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/693052022-11-17T02:08:08Zhdl_2115_45007hdl_2115_116Singularities of line congruencesIzumiya, S.Saji, K.Takeuchi, N.line congruencesnormal congruencesLagrangian congruencessingularities410A line congruence is a two parameter family of lines in IR3. In this paper we study singuÂlarities of line congruences. We show that generic singularities of general line congruences are the same as those of stable mappings between three dimensional manifolds. Moreover, we also study singularities of normal congruences and equiaffine normal congruences from the view point of the theory of Lagrangian singularities.Department of Mathematics, Hokkaido UniversityDepartmental Bulletin Paperapplication/pdfhttp://hdl.handle.net/2115/69305info:doi/10.14943/83701https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/69305/1/pre556.pdfHokkaido University Preprint Series in Mathematics5561172002-07engpublisher