Recent Comments

Recent Posts
 Some News from a Seminar in Cambridge
 Subspace Designs, Unit and Distinct Distances, and Piercing Standard Boxes.
 Greg Kuperberg @ Tel Aviv University
 Israel AGT Day, Reichman University, March 5, 2023
 Alef’s Corner: Democracy (Israel, 2023)
 Absolutely Sensational Morning News – Zander Kelley and Raghu Meka proved Behrendtype bounds for 3APs
 The Trifference Problem
 Greatest Hits 20152022, Part II
 Greatest Hits 20152022, Part I
Top Posts & Pages
 Some News from a Seminar in Cambridge
 Absolutely Sensational Morning News  Zander Kelley and Raghu Meka proved Behrendtype bounds for 3APs
 Greg Kuperberg @ Tel Aviv University
 Quantum Computers: A Brief Assessment of Progress in the Past Decade
 To cheer you up in difficult times 7: Bloom and Sisask just broke the logarithm barrier for Roth's theorem!
 'Gina Says'
 R(5,5) ≤ 48
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
 Yael Tauman Kalai's ICM2018 Paper, My Paper, and Cryptography
RSS
Tag Archives: Lou Billera
Karim Adiprasito: The gConjecture for Vertex Decomposible Spheres
J Scott Provan (site) The following post was kindly contributed by Karim Adiprasito. (Here is the link to Karim’s paper.) Update: See Karim’s comment on the needed ideas for extend the proof to the general case. See also in the … Continue reading
Posted in Combinatorics, Convex polytopes, Geometry, Guest blogger
Tagged gconjecture, J Scott Provan, Karim Adiprasito, Leonid Gurvits, Lou Billera
9 Comments
Beyond the gconjecture – algebraic combinatorics of cellular spaces I
The gconjecture for spheres is surely the one single conjecture I worked on more than on any other, and also here on the blog we had a sequence of posts about it by Eran Nevo (I,II,III,IV). Here is a great … Continue reading
Posted in Combinatorics, Convex polytopes, Geometry
Tagged Anders Bjorner, Bob MacPherson, Carl Lee, Ed Swartz, Eran Nevo, gconjecture, Günter Ziegler, Isabella Novik, June Huh, Kalle Karu, Karim Adiprasito, KazhdanLustig polynomials, Lou Billera, Marge Bayer, Peter McMullen, Richard Stanley, Ron Adin, Satoshi Murai, Tom Braden
14 Comments
(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 Carl Lee, Eran Nevo, face rings, gconjecture, Lou Billera, Peter McMullen, Polytopes, Richard Stanley
13 Comments
Euler’s Formula, Fibonacci, the BayerBillera Theorem, and Fine’s CDindex
Bill Gessley proving Euler’s formula (at UMKC) In the earlier post about Billerafest I mentioned the theorem of Bayer and Billera on flag numbers of polytopes. Let me say a little more about it. 1. Euler Euler’s theorem asserts that for … Continue reading
Posted in Combinatorics, Convex polytopes
Tagged BayerBillera's theorem, CDindex, Flag numbers, Jonathan Fine, Lou Billera, Marge Bayer
8 Comments
Billerafest
I am unable to attend the conference taking place now at Cornell, but I send my warmest greetings to Lou from Jerusalem. The titles and abstracts of the lectures can be found here. Let me tell you about two theorems by Lou. … Continue reading
Posted in Conferences, Convex polytopes
Tagged fvectors, flag vectors, gconjecture, Lou Billera
1 Comment