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 Polymath10, Post 2: Homological Approach
 Polymath10: The Erdos Rado Delta System Conjecture
 Convex Polytopes: Seperation, Expansion, Chordality, and Approximations of Smooth Bodies
 Igor Pak’s collection of combinatorics videos
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 Séminaire N. Bourbaki – Designs Exist (after Peter Keevash) – the paper
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 The KadisonSinger Conjecture has beed Proved by Adam Marcus, Dan Spielman, and Nikhil Srivastava
 Polymath10, Post 2: Homological Approach
 Polymath10: The Erdos Rado Delta System Conjecture
 New Ramanujan Graphs!
 Amazing: Peter Keevash Constructed General Steiner Systems and Designs
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
 Why is Mathematics Possible: Tim Gowers's Take on the Matter
 Can Category Theory Serve as the Foundation of Mathematics?
 Believing that the Earth is Round When it Matters
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Search Results for: Hirsch
Karim Adiprasito: Flag simplicial complexes and the nonrevisiting path conjecture
This post is authored by Karim Adiprasito The past months have seen some exciting progress on diameter bounds for polytopes and polytopal complexes, both in the negative and in the positive direction. Jesus de Loera and Steve Klee described simplicial polytopes which are not … Continue reading
Posted in Convex polytopes, Guest blogger
Tagged Convex polytopes, Flag complexes, Hirsch conjecture, Karim Adiprasito
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Some Updates
Jeff Kahn was in town: so we worked together also with Ehud Friedgut and Roy Meshulam (and others) quite intensively. Very nice! Stay tuned for a report! Polynomial Hirsch conjecture (polymath3): While the conjecture remains wide open there are some … Continue reading
Posted in Updates
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Günter Ziegler: 1000$ from Beverly Hills for a Math Problem. (IPAM remote blogging.)
Scanned letter by Zadeh. (c) Günter M. Ziegler lefttoright: David Avis, Norman Zadeh, Oliver Friedmann, and Russ Caflish (IPAM director). Photo courtesy Eddie Kim. Update: The slides for Friedmann’s talk are now available. The conference schedule page contains now the slides for … Continue reading
Posted in Computer Science and Optimization, Conferences, Guest blogger
Tagged Linear programming
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IPAM Remote Blogging: SantosWeibel 25Vertices Prismatoid and Prismatoids with large Width
Here is a web page by Christope Weibel on the improved counterexample. The IPAM webpage contains now slides of some of the lectures. Here are Santos’s slides. The last section contains some recent results on the “width of 5prismatoids” A prismatoid is a polytope … Continue reading
Is Backgammon in P?
The Complexity of ZeroSum Stochastic Games with Perfect Information Is there a polynomial time algorithm for chess? Well, if we consider the complexity of chess in terms of the board size then it is fair to think that the answer is … Continue reading
Emmanuel Abbe: Erdal Arıkan’s Polar Codes
Click here for the most recent polymath3 research thread. A new thread is comming soon. Emmanuel Abbe and Erdal Arıkan This post is authored by Emmanuel Abbe A new class of codes, called polar codes, recently made a breakthrough in … Continue reading
Roth’s Theorem: Tom Sanders Reaches the Logarithmic Barrier
Click here for the most recent polymath3 research thread. I missed Tom by a few minutes at MittagLeffler Institute a year and a half ago Suppose that is a subset of of maximum cardinality not containing an arithmetic progression of length 3. Let . … Continue reading
Posted in Combinatorics, Open problems
Tagged Endre Szemeredi, Jean Bourgain, Klaus Roth, Roger HeathBrown, Roth's theorem, Tom Sanders
9 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
Subexponential Lower Bound for Randomized Pivot Rules!
Oliver Friedmann, Thomas Dueholm Hansen, and Uri Zwick have managed to prove subexponential lower bounds of the form for the following two basic randomized pivot rules for the simplex algorithm! This is the first result of its kind and deciding … Continue reading
Budapest, Seattle, New Haven
Here we continue the previous post on Summer 2010 events in Reverse chronological order. Happy birthday Srac In the first week of August we celebrated Endre Szemeredi’s birthday. This was a very impressive conference. Panni, Endre’s wife, assisted by her … Continue reading
Posted in Blogging, Conferences
Tagged Branko Grunbaum, Conferences, Endre Szemeredi, Victor Klee
6 Comments