Recent Comments

Recent Posts
 Open problem session of HUJICOMBSEM: Problem #1, Nati Linial – Turan type theorems for simplicial complexes.
 Péter Pál Pach and Richárd Palincza: a Glimpse Beyond the Horizon
 To cheer you up 14: Hong Liu and Richard Montgomery solved the Erdős and Hajnal’s odd cycle problem
 To cheer you up in difficult times 13: Triangulating real projective spaces with subexponentially many vertices
 Benjamini and Mossel’s 2000 Account: Sensitivity of Voting Schemes to Mistakes and Manipulations
 Test Your Intuition (46): What is the Reason for Maine’s Huge Influence?
 This question from Tim Gowers will certainly cheeer you up! and test your intuition as well!
 Three games to cheer you up.
 Cheerful Test Your Intuition (#45): Survey About Sisters and Brothers
Top Posts & Pages
 Open problem session of HUJICOMBSEM: Problem #1, Nati Linial  Turan type theorems for simplicial complexes.
 Péter Pál Pach and Richárd Palincza: a Glimpse Beyond the Horizon
 To cheer you up 14: Hong Liu and Richard Montgomery solved the Erdős and Hajnal's odd cycle problem
 TYI 30: Expected number of Dice throws
 Elchanan Mossel's Amazing Dice Paradox (your answers to TYI 30)
 This question from Tim Gowers will certainly cheeer you up! and test your intuition as well!
 Cheerful Test Your Intuition (#45): Survey About Sisters and Brothers
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
 To cheer you up in difficult times 13: Triangulating real projective spaces with subexponentially many vertices
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
10 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
12 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
7 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