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Category Archives: Complex analysis
Dipoles and Pixie Dust
The purpose of this blog post is to give a short, constructive, computationfree proof of the following theorem: Theorem: Every compact subset of the Riemann sphere can be arbitrarily closely approximated (in the Hausdorff metric) by the Julia set of … Continue reading
Groups quasiisometric to planes
I was saddened to hear the news that Geoff Mess recently passed away, just a few days short of his 54th birthday. I first met Geoff as a beginning graduate student at Berkeley, in 1995; in fact, I believe he gave the … Continue reading
Kähler manifolds and groups, part 2
In this post I hope to start talking in a bit more depth about the global geometry of compact Kähler manifolds and their covers. Basic references for much of this post are the book Fundamental groups of compact Kähler manifolds by … Continue reading
Kähler manifolds and groups, part 1
One of the nice things about living in Hyde Park is the proximity to the University of Chicago. Consequently, over the summer I came in to the department from time to time to work in my office, where I have … Continue reading
Liouville illiouminated
A couple of weeks ago, my student Yan Mary He presented a nice proof of Liouville’s theorem to me during our weekly meeting. The proof was the one from BenedettiPetronio’s Lectures on Hyperbolic Geometry, which in my book gets lots … Continue reading
Posted in Complex analysis, Euclidean Geometry, Rigidity
Tagged conformal map, Liouville's theorem, Rigidity, umbilical surface
7 Comments
Kenyon’s squarespirals
The other day by chance I happened to look at Richard Kenyon’s web page, and was struck by a very beautiful animated image there. The image is of a region tiled by colored squares, which are slowly rotating. As the … Continue reading
Circle packing – theory and practice
I am spending a few months in Göttingen as a Courant Distinguished Visiting Professor, and talking a bit to Laurent Bartholdi about rational functions — i.e. holomorphic maps from the Riemann sphere to itself. A rational function is determined (up … Continue reading