non-commutative geometry
- Brauer’s forgotten group
- connected component coalgebra
- Galois and the Brauer group
- a noncommutative Grothendieck topology
- noncommutative geometry
- noncommutative geometry 2
- projects in noncommutative geometry
- points and lines
- more noncommutative manifolds
- the necklace Lie bialgebra
- the one quiver for GL(2,Z)
- representation spaces
- quiver representations
- moduli spaces
- cotangent bundles
- differential forms
- curvatures
- Brauer-Severi varieties
- smooth Brauer-Severis
- hyper-resolutions
- a cosmic Galois group
- double Poisson algebras
- A for aggregates
- B for bricks
- necklaces (again)
- seen this quiver?
- why nag? (2)
- why nag? (3)
- sexing up curves
- the Klein stack
- Alain Connes on everything
- noncommutative topology (1)
- a noncommutative topology 2
- noncommutative topology (3)
- noncommutative topology (4)
- non-geometry
- non-(commutative) geometry
- noncommutative Fourier transform
- noncommutative bookmarks
- noncommutative geometry : a medieval science?
According to a science article in the New York Times, archeologists have discovered “signs of advanced math” in medieval mosaics. An example of a quasi-crystalline Penrose pattern was found at the Darb-i Imam shrine in Isfahan, Iran.
A new study shows that the Islamic pattern-making process, far more intricate than the laying of one’s bathroom floor, appears to have involved an advanced math of quasi crystals, which was not understood by modern scientists until three decades ago. Two years ago, Peter J. Lu, a doctoral student in physics at Harvard University, was transfixed by the geometric pattern on a wall in Uzbekistan. It reminded him of what mathematicians call quasi-crystalline designs. These were demonstrated in the early 1970s by Roger Penrose, a mathematician and cosmologist at the University of Oxford. Mr. Lu set about examining pictures of other tile mosaics from Afghanistan, Iran, Iraq and Turkey, working with Paul J. Steinhardt, a Princeton cosmologist who is an authority on quasi crystals and had been Mr. Lu’s undergraduate adviser.
Penrose tilings are one of the motivating examples of Alain Connes’
book as there is a
-algebra associated to it. In fact, the algebra is AF ( a limit of
semi-simple finite dimensional algebras) so is even a formally smooth
algebra in Kontsevichian noncommutative geometry (it is remarkable how
quickly one gets used to silly terminology…). However, the Penrose
algebra is simple, so rather useless from the point of view of finite
dimensional representations… Still, Connesian noncommutative geometry
may be a recent incarnation of the medieval Tehran program (pun
intended). Thanks to
easwaran for the link
(via Technorati).
Added, March 1 : I haven’t looked at the Connes-Marcolli paper A walk in the noncommutative garden for a while but now that I do, I see that they mentioned the above already at the end of their section on Tilings (page 32). They also include clearer pictures.

arxiv, Connes, geometry, Kontsevich, Marcolli, noncommutative, representations
1 comment
Posted in geometry, rants
Written on Wed, 28 February 2007 at 10:29 am
Tags: arxiv, Connes, geometry, Kontsevich, Marcolli, noncommutative, representations
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February 28th, 2008 at 10:58 am
theory/postulation: numerical chatter is happening as we speak in some form or another [just as ied's are set off by codes] words could have mathmatical meanings such as ‘thank you god’ which is a well known islamic saying in english, etc.etc.etc. it’s the content of the context of the sentence structure and i’ve been saying that for many,many years.