Pub. Date:
Vieweg+Teubner Verlag
Ruled Varieties: An Introduction to Algebraic Differential Geometry / Edition 1

Ruled Varieties: An Introduction to Algebraic Differential Geometry / Edition 1

by Gerd Fischer, Jens Piontkowski


Current price is , Original price is $49.99. You
Select a Purchase Option (Softcover reprint of the original 1st ed. 2001)
  • purchase options
    $39.99 $49.99 Save 20% Current price is $39.99, Original price is $49.99. You Save 20%.
  • purchase options

Product Details

ISBN-13: 9783528031381
Publisher: Vieweg+Teubner Verlag
Publication date: 05/29/2001
Series: Advanced Lectures in Mathematics
Edition description: Softcover reprint of the original 1st ed. 2001
Pages: 142
Product dimensions: 6.60(w) x 9.30(h) x 0.40(d)

About the Author

Prof. Dr. em. Gerd Fischer war viele Jahre Professor für Mathematik an der Universität Düsseldorf. Er ist jetzt Gastprofessor an der Fakultät für Mathematik der TU München. Gerd Fischer ist Autor zahlreicher erfolgreicher Lehrbücher, u.a. der Linearen Algebra (vieweg studium - Grundkurs Mathematik).

Dr. Jens Piontkowski ist Hochschuldozent am Mathematischen Institut der Heinrich-Heine-Universität Düsseldorf.

Table of Contents

0 Review from Classical Differential and Projective Geometry.- 0.1 Developable Rulings.- 0.2 Vanishing Gauß Curvature.- 0.3 Hessian Matrices.- 0.4 Classification of Developable Surfaces in ?3.- 0.5 Developable Surfaces in ?3(?).- 1 Grassmannians.- 1.1 Preliminaries.- 1.1.1 Algebraic Varieties.- 1.1.2 Rational Maps.- 1.1.3 Holomorphic Linear Combinations.- 1.1.4 Limit Direction of a Holomorphic Path.- 1.1.5 Radial Paths.- 1.2 Plücker Coordinates.- 1.2.1 Local Coordinates.- 1.2.2 The Plücker Embedding.- 1.2.3 Lines in ?3.- 1.2.4 The Plücker Image.- 1.2.5 Plücker Relations.- 1.2.6 Systems of Vector Valued Functions.- 1.3 Incidences and Duality.- 1.3.1 Equations and Generators in Terms of Plücker Coordinates.- 1.3.2 Flag Varieties.- 1.3.3 Duality of Grassmannians.- 1.3.4 Dual Projective Spaces.- 1.4 Tangents to Grassmannians.- 1.4.1 Tangents to Projective Space.- 1.4.2 The Tangent Space of the Grassmannian.- 1.5 Curves in Grassmannians.- 1.5.1 The Drill.- 1.5.2 Derived Curves.- 1.5.3 Sums and Intersections.- 1.5.4 Associated Curves and Curves with Prescribed Drill.- 1.5.5 Normal Form.- 2 Ruled Varieties.- 2.1 Incidence Varieties and Duality.- 2.1.1 Unions of Linear Varieties.- 2.1.2 Fano Varieties.- 2.1.3 Joins.- 2.1.4 Conormal Bundle and Dual Variety.- 2.1.5 Duality Theorem.- 2.1.6 The Contact Locus.- 2.1.7 The Dual Curve.- 2.1.8 Rational Curves.- 2.2 Developable Varieties.- 2.2.1 Rulings.- 2.2.2 Adapted Parameterizations.- 2.2.3 Germs of Rulings.- 2.2.4 Developable Rulings and Focal Points.- 2.2.5 Developability of Joins.- 2.2.6 Dual Varieties of Cones and Degenerate Varieties.- 2.2.7 Tangent and Osculating Scrolls.- 2.2.8 Classification of Developable One Parameter Rulings.- 2.2.9 Example of a “Twisted Plane”.- 2.2.10 Characterization of Drill One Curves.- 2.3 The Gauß Map.- 2.3.1 Definition of the Gauß Map.- 2.3.2 Linearity of the Fibers.- 2.3.3 Gauß Map and Developability.- 2.3.4 Gauß Image and Dual Variety.- 2.3.5 Existence of Varieties with Given Gauß Rank.- 2.4 The Second Fundamental Form.- 2.4.1 Definition of the Second Fundamental Form.- 2.4.2 The Degeneracy Space.- 2.4.3 The Degeneracy Map.- 2.4.4 The Singular and Base Locus.- 2.4.5 The Codimension of a Uniruled Variety.- 2.4.6 Fibers of the Gauß Map.- 2.4.7 Characterization of Gauß Images.- 2.4.8 Singularities of the Gauß Map.- 2.5 Gauß Defect and Dual Defect.- 2.5.1 Dual Defect of Segre Varieties.- 2.5.2 Gauß Defect and Singular Locus.- 2.5.3 Dual Defect and Singular Locus.- 2.5.4 Computation of the Dual Defect.- 2.5.5 The Surface Case.- 2.5.6 Classification of Developable Hypersurfaces.- 2.5.7 Dual Defect of Uniruled Varieties.- 2.5.8 Varieties with Very Small Dual Varieties.- 3 Tangent and Secant Varieties.- 3.1 Zak’s Theorems.- 3.1.1 Tangent Spaces, Tangent Cones, and Tangent Stars.- 3.1.2 Zak’s Theorem on Tangent and Secant Varieties.- 3.1.3 Theorem on Tangencies.- 3.2 Third and Higher Fundamental Forms.- 3.2.1 Definition.- 3.2.2 Vanishing of Fundamental Forms.- 3.3 Tangent Varieties.- 3.3.1 The Dimension of the Tangent Variety.- 3.3.2 Developability of the Tangent Variety.- 3.3.3 Singularities of the Tangent Variety.- 3.4 The Dimension of the Secant Variety.- List of Symbols.


Click to read or download

Customer Reviews

Most Helpful Customer Reviews

See All Customer Reviews