- Alef Corner: Math Collaboration
- Alef’s Corner: Math Collaboration 2
- To cheer you up in difficult times 11: Immortal Songs by Sabine Hossenfelder and by Tom Lehrer
- To cheer you up in difficult times 10: Noam Elkies’ Piano Improvisations and more
- Quantum Matters
- To cheer you up in difficult times 9: Alexey Pokrovskiy proved that Rota’s Basis Conjecture holds asymptotically
- To Cheer you up in Difficult Times 8: Nathan Keller and Ohad Klein Proved Tomaszewski’s Conjecture on Randomly Signed Sums
- Noam Lifshitz: A new hypercontractivity inequality — The proof!
- To cheer you up in difficult times 7: Bloom and Sisask just broke the logarithm barrier for Roth’s theorem!
Top Posts & Pages
- TYI 30: Expected number of Dice throws
- Quantum Matters
- Gil's Collegial Quantum Supremacy Skepticism FAQ
- To Cheer you up in Difficult Times 8: Nathan Keller and Ohad Klein Proved Tomaszewski's Conjecture on Randomly Signed Sums
- Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
- A sensation in the morning news - Yaroslav Shitov: Counterexamples to Hedetniemi's conjecture.
- Elchanan Mossel's Amazing Dice Paradox (your answers to TYI 30)
- Extremal Combinatorics IV: Shifting
- Are Natural Mathematical Problems Bad Problems?
Monthly Archives: February 2015
Combinatorics and More’s Greatest Hits First Month Combinatorics, Mathematics, Academics, Polemics, … Helly’s Theorem, “Hypertrees”, and Strange Enumeration I (There were 3 follow up posts:) Extremal Combinatorics I: Extremal Problems on Set Systems (There were 4 follow up posts II ; III; IV; VI) Drachmas Rationality, Economics and … Continue reading
With Ilan, my four month old grandson
A quick schematic road-map to these new geometric objects. The positroidron can be seen as a cellular structure on the nonnegative Grassmanian – the part of the real Grassmanian G(m,n) which corresponds to m by n matrices with all m by … Continue reading
The topological Tverberg conjecture (discussed in this post), a holy grail of topological combinatorics, was refuted! The three-page paper “Counterexamples to the topological Tverberg conjecture” by Florian Frick gives a brilliant proof that the conjecture is false. The proof is … Continue reading