Discontinuous groups in some metric and nonmetric spaces
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.
Discussion algébrique de l’équation en
Discussion de l'intersection de deux surfaces du second ordre
Disegni divisibili e loro automorfismi
Disjoint and complete unions of incidence structures
Some decompositions of general incidence structures with regard to distinguished components (modular or simple) are considered and several structure theorems for them are deduced.
Disjoint unions of incidence structures and complete lattices
Dissections into equilateral triangles.
Dissections of a Polygon.
Dissections of Regular Polygons into Triangles of Equal Areas.
Distance formulas in complex hyperbolic space.
Distance preserving mappings of Grassmann graphs.
Distance theorems in geometry.
Distance-preserving maps in generalized polygons. I: Maps on flags.
Distance-preserving maps in generalized polygons. II: Maps on points and/or lines.
Distances of Heegaard splittings.
Distributions and heat equation in
Dividing an arc to subarcs with equal chords
Dividing the Sides of a Triangle in Proportional Parts
Divisible designs admitting a Suzuki group as an automorphism group
Si costruiscono, facendo uso delle rette dei piani di Lüneburg e degli ovali di Tits, due classi di disegni divisibili ipersemplici che ammettono il gruppo di Suzuki ( con ) come gruppo di automorfismi. Inoltre si studiano le strutture ottenute determinandone le orbite di .