Category Archives: Guest blogger

To cheer you up in difficult times 32, Annika Heckel’s guest post: How does the Chromatic Number of a Random Graph Vary?

This is a guest post kindly written by Annika Heckel. We first reported about Annika Heckel’s breakthrough in this post. A pdf version of this post can be found here. Pick an -vertex graph uniformly at random. Pick another one. … Continue reading

Posted in Combinatorics, Guest blogger, Probability | Tagged | Leave a comment

Open problem session of HUJI-COMBSEM: Problem #4, Eitan Bachmat: Weighted Statistics for Permutations

This is a continuation of our series of posts on the HUJI seminar 2020 open problems. This time the post was kindly written by Eitan Bachmat who proposed the problem.  My summary: understanding of the distribution of largest increasing subsequences … Continue reading

Posted in Combinatorics, Guest blogger, Probability | Tagged | 4 Comments

Noam Lifshitz: A new hypercontractivity inequality — The proof!

This is a guest post kindly contributed by Noam Lifshitz. Here is a pdf version.  This post is a continuation of the post  To cheer you up in difficult times 3: A guest post by Noam Lifshitz on the new … Continue reading

Posted in Analysis, Combinatorics, Guest blogger | Tagged | Leave a comment

To cheer you up in difficult times 3: A guest post by Noam Lifshitz on the new hypercontractivity inequality of Peter Keevash, Noam Lifshitz, Eoin Long and Dor Minzer

This is a guest post kindly contributed by Noam Lifshitz. My short introduction: There is nothing like a new hypercontractivity inequality to cheer you up in difficult times and this post describes an amazing new hypercontractivity inequality.  The post describes … Continue reading

Posted in Analysis, Combinatorics, Computer Science and Optimization, Guest blogger, Poetry, Probability | Tagged , , , , | 4 Comments

Dan Romik on the Riemann zeta function

This post, about the Riemann zeta function, which is among the most important and mysterious mathematical objects was kindly written by Dan Romik. It is related to his paper Orthogonal polynomial expansions for the Riemann xi function,  that we mentioned … Continue reading

Posted in Combinatorics, Guest blogger, Number theory | Tagged , , , , | 2 Comments

Imre Bárány: Limit shape

Limit shapes are fascinating objects in the interface between probability and geometry and between the discrete and the continuous. This post is kindly contributed by Imre Bárány. What is a limit shape? There are finitely many convex lattice polygons contained … Continue reading

Posted in Combinatorics, Convexity, Geometry, Guest blogger, Probability | Tagged , | 4 Comments

Karim Adiprasito: The g-Conjecture 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 , , , , | 9 Comments

Ladies and Gentlemen, Stan Wagon: TYI 32 – A Cake Problem.

The following post was kindly contributed by Stan Wagon. Stan (Wikipedea) is famous for his books, papers, snow-sculptures, and square-wheels bicycles (see picture below) !     A round cake has icing on the top but not the bottom. Cut out a … Continue reading

Posted in Combinatorics, Guest blogger, Test your intuition | Tagged , , | 8 Comments

Eran Nevo: g-conjecture part 4, Generalizations and Special Cases

This is the fourth in a series of posts by Eran Nevo on the g-conjecture. Eran’s first post was devoted to the combinatorics of the g-conjecture and was followed by a further post by me on the origin of the g-conjecture. Eran’s second post was about … Continue reading

Posted in Combinatorics, Convex polytopes, Guest blogger, Open problems | Tagged , | 2 Comments

Thilo Weinert: Transfinite Ramsey Numbers

This is first of three posts kindly written by Thilo Weinert Recently Gil asked me whether I would like to contribute to his blog and I am happy to do so. I enjoy both finite and infinite combinatorics and it … Continue reading

Posted in Combinatorics, Guest blogger, Logic and set theory | Tagged | 3 Comments