-
Recent Posts
- Bing’s wild involution
- Stiefel-Whitney cycles as intersections
- Schläfli – for lush, voluminous polyhedra
- Slightly elevated Teichmuller theory
- Mr Spock complexes (after Aitchison)
- Roots, Schottky semigroups, and Bandt’s Conjecture
- Taut foliations and positive forms
- Explosions – now in glorious 2D!
- Dipoles and Pixie Dust
- Mapping class groups: the next generation
- Groups quasi-isometric to planes
- Div, grad, curl and all this
- A tale of two arithmetic lattices
- 3-manifolds everywhere
- kleinian, a tool for visualizing Kleinian groups
- Kähler manifolds and groups, part 2
- Kähler manifolds and groups, part 1
- Liouville illiouminated
- Scharlemann on Schoenflies
- You can solve the cube – with commutators!
- Chiral subsurface projection, asymmetric metrics and quasimorphisms
- Random groups contain surface subgroups
- wireframe, a tool for drawing surfaces
- Cube complexes, Reidemeister 3, zonohedra and the missing 8th region
- Orthocentricity
Blogroll
- 0xDE
- Area 777
- Bluefawnpinkmanga
- Combinatorics and more
- Deep street soul
- Evaluating E-Discovery
- floerhomology
- Gaddeswarup
- Geometric Group Theory
- Godel's lost letter and P=NP
- Images des mathematiques
- Jim Woodring
- Language Log
- Letters of note
- Low dimensional topology
- Math Overflow
- Math/Art Blog
- Mathematics under the microscope
- n-Category Cafe
- Noncommutative geometry
- Paul Krugman
- Persiflage
- Preposterous Universe
- Questionable content
- Quomodocumque
- Real Climate
- Scott McCloud
- Secret blogging seminar
- Sketches of topology
- Tanya Khovanova
- Terry Tao
- Tim Gowers
- Tony Phillips
Books
Software
Recent Comments
tiktok downloader on Bing’s wild involution Groups for which qua… on Big mapping class groups and… Anonymous on Stiefel-Whitney cycles as… Anonymous on Stiefel-Whitney cycles as… Israel Socratus Sado… on Bing’s wild involution Categories
- 3-manifolds (21)
- 4-manifolds (2)
- Algebraic Geometry (2)
- Algebraic Topology (1)
- Biology (2)
- Commentary (4)
- Complex analysis (11)
- Convex geometry (2)
- Diophantine approximation (1)
- Dynamics (13)
- Ergodic Theory (8)
- Euclidean Geometry (8)
- Foliations (2)
- Geometric structures (6)
- Groups (31)
- Hyperbolic geometry (25)
- Knot theory (1)
- Lie groups (8)
- Number theory (2)
- Overview (2)
- Polyhedra (3)
- Probability (1)
- Projective geometry (2)
- Psychology (3)
- Riemannian geometry (1)
- Rigidity (2)
- Special functions (2)
- Surfaces (20)
- Symplectic geometry (3)
- TQFT (1)
- Uncategorized (6)
- Visualization (10)
Meta
Category Archives: Projective geometry
Slightly elevated Teichmuller theory
Last week at my invitation, David Dumas spoke in the U Chicago geometry seminar and gave a wonderful introductory talk on the theory of convex real projective structures on surfaces. This is the first step on the road to what is colloquially known … Continue reading
Zonohedra and the Sylvester-Gallai theorem
When I was in Melbourne recently, I spent some time browsing through a copy of “Twelve Geometric Essays” by Harold Coxeter in the (small) library at AMSI. One of these essays was entitled “The classification of zonohedra by means of … Continue reading
Posted in Polyhedra, Projective geometry
Tagged Coxeter, projective plane, Sylvester-Gallai theorem, zonohedra
5 Comments
Geometry and the imagination 