A characterization of collineations by order geometry.
A generalization of the Schwarzian via Clifford numbers.
A non-homogeneous, symmetric contact projective structure
We construct a non-homogeneous contact projective structure which is symmetric from the point of view of parabolic geometries.
A projective characterization of the Veronese surface
Alcuni invarianti di contatto di due varietà in uno spazio proiettivo
Algebraic geometry and local differential geometry
Applications of spectral geometry to affine and projective geometry.
Bertrand curves in Galilean space and their characterizations
Branch Points of Conformal Mappings of Surfaces.
Classification of homogeneous submanifolds in homogeneous spaces.
Classification of projective space motions with only plane trajectories
The paper contains the solution of the classification problem for all motions in the complex projective space, which have only plane trajectories. It is shown that each such motion is a submanifold of a maximal motion with the same property. Maximal projective space motions with only plane trajectories are determined by special linear submanifolds of dimensions 2, 3, 5, 8 in , they are denoted as and given by explicit expressions.
Contribution to the theory of pseudocongruences with projective connection
Deformations of plane pseudocongruences with projective connection
Developable hypersurfaces and homogeneous spaces in a real projective space.
Die Projektivabwicklung zweiter und dritter Ordnung von Ebenenkongruenzen im achtdimensionalen projektiven Raum
Die zweifachen Blutelschen Kegelschnittflächen.
Differential Geometry of Complex Projective Space Curves.
Differential geometry of surfaces
Differential invariants of conformal and projective surfaces.
Discrete Laplace cycles of period four
We study discrete conjugate nets whose Laplace sequence is of period four. Corresponding points of opposite nets in this cyclic sequence have equal osculating planes in different net directions, that is, they correspond in an asymptotic transformation. We show that this implies that the connecting lines of corresponding points form a discrete W-congruence. We derive some properties of discrete Laplace cycles of period four and describe two explicit methods for their construction.