Recent Comments

Recent Posts
 AlexFest: 60 Faces of Groups
 Postoctoral Positions with Karim and Other Announcements!
 Jirka
 AviFest, AviStories and Amazing Cash Prizes.
 Polymath 10 post 6: The ErdosRado sunflower conjecture, and the Turan (4,3) problem: homological approaches.
 Polymath 10 Emergency Post 5: The ErdosSzemeredi Sunflower Conjecture is Now Proven.
 Mind Boggling: Following the work of Croot, Lev, and Pach, Jordan Ellenberg settled the cap set problem!
 More Math from Facebook
 The Erdős Szekeres polygon problem – Solved asymptotically by Andrew Suk.
Top Posts & Pages
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
 Believing that the Earth is Round When it Matters
 A Breakthrough by Maryna Viazovska Leading to the Long Awaited Solutions for the Densest Packing Problem in Dimensions 8 and 24
 The Simplex, the Cyclic polytope, the Positroidron, the Amplituhedron, and Beyond
 Mind Boggling: Following the work of Croot, Lev, and Pach, Jordan Ellenberg settled the cap set problem!
 In how many ways you can chose a committee of three students from a class of ten students?
 The KadisonSinger Conjecture has beed Proved by Adam Marcus, Dan Spielman, and Nikhil Srivastava
 When It Rains It Pours
 Can Category Theory Serve as the Foundation of Mathematics?
RSS
Author Archives: Gil Kalai
זה הזמן לשינוי
זו הפעם החמשעשרה שבה אצביע והפעם השלישית שאנו נמצאים לפני בחירות מאז שהתחלתי בכתיבת הבלוג. בעבר לא הבעתי בפומבי את הבחירה האישית שלי. עבורי יום הבחירות הוא יום חג, ההכרעות בין תפיסות עולם ואינטרסים מנוגדים אינן קלות, ויש דרכים שונות, … Continue reading
Combinatorics and More – Greatest Hits
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
Posted in Uncategorized
Leave a comment
The Simplex, the Cyclic polytope, the Positroidron, the Amplituhedron, and Beyond
A quick schematic roadmap 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
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, Uli Wagner
2 Comments
Midrasha Mathematicae #18: In And Around Combinatorics
Tahl Nowik Update 3 (January 30): The midrasha ended today. Update 2 (January 28): additional videos are linked; Update 1 (January 23): Today we end the first week of the school. David Streurer and Peter Keevash completed … Continue reading
Posted in Combinatorics, Conferences, Updates
1 Comment
A Historical Picture Taken by Nimrod Megiddo
Last week I took a bus from Tel Aviv to Jerusalem and I saw (from behind) a person that I immediately recognized. It was Nimrod Megiddo, from IBM Almaden, one of the very first to relate game theory with complexity … Continue reading
Scott Triumphs* at the Shtetl
Scott Aaronson wrote a new post on the Shtetl Optimized** reflecting on the previous thread (that I referred to in my post on Amy’s triumph), and on reactions to this thread. The highlight is a list of nine of Scott’s … Continue reading
Amy Triumphs* at the Shtetl
It was not until the 144th comment by a participants named Amy on Scott’s Aaronson recent Shtetloptimized** post devoted to a certain case of sexual harassment at M. I. T. that the discussion turned into something quite special. Amy’s great … Continue reading
Posted in Controversies and debates, Women in science
Tagged Amy, feminism, Shtetloptimized
23 Comments