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 Why Quantum Computers Cannot Work: The Movie!
 Levon Khachatrian’s Memorial Conference in Yerevan
 NavierStokes Fluid Computers
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 Amazing: Peter Keevash Constructed General Steiner Systems and Designs
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 Why Quantum Computers Cannot Work: The Movie!
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 Itai Ashlagi, Yashodhan Kanoria, and Jacob Leshno: What a Difference an Additional Man makes?
 Polymath 8  a Success!
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
 The KadisonSinger Conjecture has beed Proved by Adam Marcus, Dan Spielman, and Nikhil Srivastava
 NavierStokes Fluid Computers
 In how many ways you can chose a committee of three students from a class of ten students?
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Category Archives: Open problems
Around the CapSet problem (B)
Part B: Finding special cap sets This is a second part in a 3part series about variations on the cap set problem that I studied with Roy Meshulam. (The first post is here.) I will use here a different notation than in part … Continue reading
A Problem on Planar Percolation
Conjecture (Gady Kozma): Prove that the critical probability for planar percolation on a Cayley graph of the group is always an algebraic number. Gady mentioned this conjecture in his talk here about percolation on infinite Cayley graphs. (Update April 30: Today Gady mentioned … Continue reading
(Eran Nevo) The gConjecture II: The Commutative Algebra Connection
Richard Stanley This post is authored by Eran Nevo. (It is the second in a series of five posts.) The gconjecture: the commutative algebra connection Let be a triangulation of a dimensional sphere. Stanley’s idea was to associate with a ring … Continue reading
How the gConjecture Came About
This post complements Eran Nevo’s first post on the conjecture 1) Euler’s theorem Euler Euler’s famous formula for the numbers of vertices, edges and faces of a polytope in space is the starting point of many mathematical stories. (Descartes came close … Continue reading
(Eran Nevo) The gConjecture I
This post is authored by Eran Nevo. (It is the first in a series of five posts.) Peter McMullen The gconjecture What are the possible face numbers of triangulations of spheres? There is only one zerodimensional sphere and it consists … Continue reading
Posted in Combinatorics, Convex polytopes, Guest blogger, Open problems
Tagged face rings, gconjecture, Polytopes
5 Comments
An Open Discussion and Polls: Around Roth’s Theorem
Suppose that is a subset of of maximum cardinality not containing an arithmetic progression of length 3. Let . How does behave? We do not really know. Will it help talking about it? Can we somehow look beyond the horizon and try to guess what … Continue reading
Posted in Combinatorics, Open discussion, Open problems
Tagged Cap sets, polymath1, Roth's theorem, Szemeredi's theorem
24 Comments
Rosenfeld’s OddDistance Problem
Moshe Rosenfeld’s odddistance problem: Let G be the graph whose vertices are points in the plane and two vertices form an edge if their distance is an odd integer. Is the chromatic number of this graph finite?
Posted in Combinatorics, Open problems
1 Comment
FranklRodl’s Theorem and Variations on the Cap Set Problem: A Recent Research Project with Roy Meshulam (A)
Voita Rodl I would like to tell you about a research project in progress with Roy Meshulam. (We started it in the summer, but then moved to other things; so far there are interesting insights, and perhaps problems, but not substantial … Continue reading
Posted in Combinatorics, Open problems
Tagged Cap sets, Extremal combinatorics, Intersection theorems, polymath1
6 Comments
Telling a Simple Polytope From its Graph
Peter Mani (a photograph by Emo Welzl) Simple polytopes, puzzles Micha A. Perles conjectured in the ’70s that the graph of a simple polytope determines the entire combinatorial structure of the polytope. This conjecture was proved in 1987 by Blind … Continue reading
Posted in Convex polytopes, Open problems
Tagged Eric Friedman, Peter Mani, Roswitta Blind
4 Comments
Lovasz’s Two Families Theorem
Laci and Kati This is the first of a few posts which are spinoffs of the extremal combinatorics series, especially of part III. Here we talk about Lovasz’s geometric two families theorem. 1. Lovasz’s two families theorem Here … Continue reading
Posted in Combinatorics, Convexity, Open problems
Tagged exterior algebras, Extremal combinatorics, shellability
4 Comments