Jan Techter

techter at math dot tu minus berlin dot de

AG Geometrie und mathematische Physik
Intstitut für Mathematik
TU Berlin
Strasse des 17. Juni 136,
10623 Berlin, Germany

Office: MA 880


  • Geometry, Differential Geometry, Discrete Differential Geometry
Projects Books
Conferences and workshops



Lecture notes
  • WS23/24: Mathematical Visualization
    Projective geometry, Desargues' theorem, affine classification of conics and quadrics, shadows of quadrics, plane curves, osculating circle, evolute, involute, Möbius geometry of plane curves, roulettes of curves, cycloidal pendulum, elliptic billiards, caustics, envelopes and orthogonal trajectories of families of circles, tractrix and Darboux transform, midcircles, ruled and developable surfaces, curvature line parametrizations, focal surfaces, principal curvature spheres, channel surfaces, Dupin cyclides.
  • WS21/22: Confocal quadrics, their discretization, and related topics
    smooth/discrete orthogonal nets, smooth/discrete curvature line parametrizations, smooth/discrete confocal quadrics, diagonally related nets on surfaces, classification of pencils of quadrics.
  • SS21: Non-Euclidean Geometries (with notes)
    Möbius geometry, Laguerre geometry, Lie geometry, Plücker geometry, curves and surfaces in these geometries.
  • SS20: Non-Euclidean Geometries
    Projective geometry, projective configurations, quadrics, Klein Erlangen program, classification of (dual) pencils of conics, Graves-Chasles theorem, incircular nets, Laguerre geometry, hypercycles, checkerboard incircular nets.
  • SS14: Discrete Differential Geometry
    Discrete curves: curvatures, flows, elastica, Darboux transforms;
    Discrete surfaces: abstract discrete surfaces, polyhedral surfaces, piecewise flat surfaces, discrete cotan Laplace operator, Delaunay tessellations, line congrueneces over simplicial surfaces, polyhedral surfaces with parallel Gauss map, Willmore energy.
Plain Academic