Recent Comments

Recent Posts
 Peter Cameron: Doing research
 To cheer you up in difficult times 18: Beautiful drawings by Neta Kalai for my book: “Gina Says”
 Amazing: Simpler and more general proofs for the gtheorem by Stavros Argyrios Papadakis and Vasiliki Petrotou, and by Karim Adiprasito, Stavros Argyrios Papadakis, and Vasiliki Petrotou.
 Igor Pak: What if they are all wrong?
 To cheer you up in difficult times 17: Amazing! The ErdősFaberLovász conjecture (for large n) was proved by Dong Yeap Kang, Tom Kelly, Daniela Kühn, Abhishek Methuku, and Deryk Osthus!
 Open problem session of HUJICOMBSEM: Problem #5, Gil Kalai – the 3ᵈ problem
 To cheer you up in difficult times 16: Optimism, two quotes
 The Argument Against Quantum Computers – A Very Short Introduction
 Open problem session of HUJICOMBSEM: Problem #4, Eitan Bachmat: Weighted Statistics for Permutations
Top Posts & Pages
 Peter Cameron: Doing research
 TYI 30: Expected number of Dice throws
 Amazing: Simpler and more general proofs for the gtheorem by Stavros Argyrios Papadakis and Vasiliki Petrotou, and by Karim Adiprasito, Stavros Argyrios Papadakis, and Vasiliki Petrotou.
 Igor Pak: What if they are all wrong?
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
 The Argument Against Quantum Computers  A Very Short Introduction
 Chomskian Linguistics
 Dan Romik on the Riemann zeta function
 To cheer you up in difficult times 18: Beautiful drawings by Neta Kalai for my book: "Gina Says"
RSS
Tag Archives: Oberwolfach
Richard Ehrenborg’s problem on spanning trees in bipartite graphs
Richard Ehrenborg with a polyhedron In the Problem session last Thursday in Oberwolfach, Steve Klee presented a beautiful problem of Richard Ehrenborg regarding the number of spanning trees in bipartite graphs. Let be a bipartite graph with vertices on one … Continue reading
Mohammad Ghomi and Joel Spruck settled the CartanHadamard conjecture!
Greetings from Oberwolfach from a great conference on algebraic, geometric, and topological combinatorics. Stay tuned for more pictures and updates from Oberwolfach and CERN, and also in case you did not see it already here is the link to the … Continue reading
Posted in Geometry
Tagged CartanHadamard's conjecture, Joel Spruck, Mohammad Ghomi, Oberwolfach
5 Comments
From Oberwolfach: The Topological Tverberg Conjecture is False
The topological Tverberg conjecture (discussed in this post), a holy grail of topological combinatorics, was refuted! The threepage paper “Counterexamples to the topological Tverberg conjecture” by Florian Frick gives a brilliant proof that the conjecture is false. The proof is … Continue reading
Posted in Combinatorics, Conferences, Convexity, Updates
Tagged Florian Frick, Issac Mabillard, Oberwolfach, Uli Wagner
3 Comments
My Mathematical Dialogue with Jürgen Eckhoff
Jürgen Eckhoff, Ascona 1999 Jürgen Eckhoff is a German mathematician working in the areas of convexity and combinatorics. Our mathematical paths have met a remarkable number of times. We also met quite a few times in person since our first … Continue reading
Posted in Combinatorics, Convex polytopes, Open problems
Tagged Andy Frohmader, Helly's theorem, Jurgen Eckhoff, Nina Amenta, Noga Alon, Oberwolfach, Roy Meshulam
1 Comment
Amazing: Peter Keevash Constructed General Steiner Systems and Designs
Here is one of the central and oldest problems in combinatorics: Problem: Can you find a collection S of qsubsets from an nelement set X set so that every rsubset of X is included in precisely λ sets in the collection? … Continue reading
Posted in Combinatorics, Open problems
Tagged Combinatorics, Designs, Oberwolfach, Peter Keevash
16 Comments