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Recent Posts
 Call for nominations for the Ostrowski Prize 2017
 Problems for Imre Bárány’s Birthday!
 Twelves short videos about members of the Department of Mathematics and Statistics at the University of Victoria
 Jozsef Solymosi is Giving the 2017 Erdős Lectures in Discrete Mathematics and Theoretical Computer Science
 Updates (belated) Between New Haven, Jerusalem, and TelAviv
 Oded Goldreich Fest
 The Race to Quantum Technologies and Quantum Computers (Useful Links)
 Around the GarsiaStanley’s Partitioning Conjecture
 My Answer to TYI 28
Top Posts & Pages
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
 The Race to Quantum Technologies and Quantum Computers (Useful Links)
 Emmanuel Abbe: Erdal Arıkan's Polar Codes
 R(5,5) ≤ 48
 Polymath 10 Emergency Post 5: The ErdosSzemeredi Sunflower Conjecture is Now Proven.
 Updates and plans III.
 Believing that the Earth is Round When it Matters
 Can Category Theory Serve as the Foundation of Mathematics?
 Analysis of Boolean Functions
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Category Archives: Geometry
Andriy Bondarenko Showed that Borsuk’s Conjecture is False for Dimensions Greater Than 65!
The news in brief Andriy V. Bondarenko proved in his remarkable paper The Borsuk Conjecture for twodistance sets that the Borsuk’s conjecture is false for all dimensions greater than 65. This is a substantial improvement of the earlier record (all dimensions … Continue reading
Symplectic Geometry, Quantization, and Quantum Noise
Over the last two meetings of our HU quantum computation seminar we heard two talks about symplectic geometry and its relations to quantum mechanics and quantum noise. Yael Karshon: Manifolds, symplectic manifolds, Newtonian mechanics, quantization, and the non squeezing theorem. … Continue reading
Greg Kuperberg: It is in NP to Tell if a Knot is Knotted! (under GRH!)
Wolfgang Haken found an algorithm to tell if a knot is trivial, and, more generally with Hemion, if two knots are equivalent. Joel Hass, Jeff Lagarias and Nick Pippinger proved in 1999 that telling that a knot is unknotted is … Continue reading
Exciting News on Three Dimensional Manifolds
The Virtually Haken Conjecture A Haken 3manifold is a compact 3dimensional manifold M which is irreducible (in a certain strong sense) but contains an incompressible surface S. (An embedded surface S is incompressible if the embedding indices an injection of its … Continue reading
Fractional SylvesterGallai
Avi Wigderson was in town and gave a beautiful talk about an extension of SylvesterGallai theorem. Here is a link to the paper: Rank bounds for design matrices with applications to combinatorial geometry and locally correctable codes by Boaz Barak, Zeev … Continue reading
Posted in Combinatorics, Computer Science and Optimization, Geometry
Tagged Avi Wigderson, Codes, Greg Kuperberg, SylvesterGallai
4 Comments
Course Announcement: High Dimensional Expanders
Alex Lubotzky and I are running together a year long course at HU on High Dimensional Expanders. High dimensional expanders are simplical (and more general) cell complexes which generalize expander graphs. The course will take place in Room 110 of the mathematics building … Continue reading
Posted in Algebra and Number Theory, Combinatorics, Geometry, Teaching
2 Comments
Polymath3 (PHC6): The Polynomial Hirsch Conjecture – A Topological Approach
This is a new polymath3 research thread. Our aim is to tackle the polynomial Hirsch conjecture which asserts that there is a polynomial upper bound for the diameter of graphs of dimensional polytopes with facets. Our research so far was … Continue reading
Posted in Convex polytopes, Geometry, Polymath3
Tagged Hirsch conjecture, Polymath3, Topological combinatorics
37 Comments
János Pach: Guth and Katz’s Solution of Erdős’s Distinct Distances Problem
Click here for the most recent polymath3 research thread. Erdős and Pach celebrating another November day many years ago. The Wolf disguised as Little Red Riding Hood. Pach disguised as another Pach. This post is authored by János Pach A … Continue reading
Posted in Combinatorics, Geometry, Guest blogger, Open problems
Tagged Larry Guth, Nets Hawk Katz
13 Comments
Benoît’s Fractals
Mandelbrot set Benoît Mandelbrot passed away a few dayes ago on October 14, 2010. Since 1987, Mandelbrot was a member of the Yale’s mathematics department. This chapterette from my book “Gina says: Adventures in the Blogosphere String War” about fractals is brought here on this … Continue reading
Posted in Geometry, Obituary, Physics, Probability
6 Comments