On singular projective deformations of two second class totally focal pseudocongruences of planes

Let C:L→L¯ be a projective deformation of the second order of two totally focal pseudocongruences L and L¯ of (m−1)-planes in projective spaces Pn and P¯n, 2m−1≤n<3m−1, and let K be a collineation realizing such a C. The deformation C is said to be weakly singular, singular, or α-strongly singula...

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Main Author: Ludmila Goldberg
Format: Article
Language:English
Published: Wiley 1988-01-01
Series:International Journal of Mathematics and Mathematical Sciences
Subjects:
Online Access:http://dx.doi.org/10.1155/S0161171288000110
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author Ludmila Goldberg
author_facet Ludmila Goldberg
author_sort Ludmila Goldberg
collection DOAJ
description Let C:L→L¯ be a projective deformation of the second order of two totally focal pseudocongruences L and L¯ of (m−1)-planes in projective spaces Pn and P¯n, 2m−1≤n<3m−1, and let K be a collineation realizing such a C. The deformation C is said to be weakly singular, singular, or α-strongly singular, α=3,4,…, if the collineation K gives projective deformations of order 1, 2 or α of all corresponding focal surfaces of L and L¯. It is proved that C is weakly singular and conditions are found for C to be singular. The pseudocongruences L and L¯ are identical if and only if C is 3-strongly singular.
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institution Kabale University
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series International Journal of Mathematics and Mathematical Sciences
spelling doaj-art-38485e0db5324e7b8106f7116b5d8bb12025-02-03T01:20:59ZengWileyInternational Journal of Mathematics and Mathematical Sciences0161-17121687-04251988-01-01111718010.1155/S0161171288000110On singular projective deformations of two second class totally focal pseudocongruences of planesLudmila Goldberg0Department of Mathematics, New Jersey Institute of Technology, Newark 07102, New Jersey, USALet C:L→L¯ be a projective deformation of the second order of two totally focal pseudocongruences L and L¯ of (m−1)-planes in projective spaces Pn and P¯n, 2m−1≤n<3m−1, and let K be a collineation realizing such a C. The deformation C is said to be weakly singular, singular, or α-strongly singular, α=3,4,…, if the collineation K gives projective deformations of order 1, 2 or α of all corresponding focal surfaces of L and L¯. It is proved that C is weakly singular and conditions are found for C to be singular. The pseudocongruences L and L¯ are identical if and only if C is 3-strongly singular.http://dx.doi.org/10.1155/S0161171288000110pseudocongruenceprojective deformationsingular projective deformationfocal surface.
spellingShingle Ludmila Goldberg
On singular projective deformations of two second class totally focal pseudocongruences of planes
International Journal of Mathematics and Mathematical Sciences
pseudocongruence
projective deformation
singular projective deformation
focal surface.
title On singular projective deformations of two second class totally focal pseudocongruences of planes
title_full On singular projective deformations of two second class totally focal pseudocongruences of planes
title_fullStr On singular projective deformations of two second class totally focal pseudocongruences of planes
title_full_unstemmed On singular projective deformations of two second class totally focal pseudocongruences of planes
title_short On singular projective deformations of two second class totally focal pseudocongruences of planes
title_sort on singular projective deformations of two second class totally focal pseudocongruences of planes
topic pseudocongruence
projective deformation
singular projective deformation
focal surface.
url http://dx.doi.org/10.1155/S0161171288000110
work_keys_str_mv AT ludmilagoldberg onsingularprojectivedeformationsoftwosecondclasstotallyfocalpseudocongruencesofplanes