Combinatorics and More’s Greatest Hits (April 2008- February 2015)
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 Games
Open problems
Five Open Problems Regarding Convex Polytopes
Seven Problems Around Tverberg’s Theorem
F ≤ 4E
The AC0 Prime Number Conjecture
Coloring Simple Polytopes and Triangulations
Some old and new problems in combinatorics and geometry
Noise Stability and Threshold Circuits
Taxi and other Stories
Cosmonaut: Michal Linial
Michal Linial: No Witches in Portugal
Tel-Aviv’s “Jerusalem Beach”
Coffee, Cigarettes, and Aggression
Polytopes
Ziegler´s Lecture on the Associahedron
The Simplex, the Cyclic polytope, the Positroidron, the Amplituhedron, and Beyond
Satoshi Murai and Eran Nevo proved the Generalized Lower Bound Conjecture.
Telling a Simple Polytope From its Graph
Combinatorics
When Do a Few Colors Suffice?
Fractional Sylvester-Gallai
My Mathematical Dialogue with Jürgen Eckhoff
Influence, Threshold, and Noise
Quantum
A Few Slides and a Few Comments From My MIT Lecture on Quantum Computers
Why Quantum Computers Cannot Work: The Movie!
Symplectic Geometry, Quantization, and Quantum Noise
Aaronson and Arkhipov’s Result on Hierarchy Collapse
Computing
Is Backgammon in P?
Four Derandomization Problems
Navier-Stokes Fluid Computers
Subexponential Lower Bound for Randomized Pivot Rules!
Impagliazzo’s Multiverse
Economics and Rationality
Arrow’s Economics 1
Social Choice Talk
Sex, football, and other sports
Academic Degrees and Sex
The Intermediate Value Theorem Applied to Football
Is More Sex Safe? A book review.
Guests posts
Emmanuel Abbe: Erdal Arıkan’s Polar Codes
János Pach: Guth and Katz’s Solution of Erdős’s Distinct Distances Problem
Amir Ban on Deep Junior
About Conjectures: Shmuel Weinberger
(Eran Nevo) The g-Conjecture I
Christine Bjorner: The Golden Room and the Golden Mountain
Polls
What does “beyond a reasonable doubt” practically mean?
Would you decide the election if you could?
The Generation Gap
People
Oded
Happy Birthday Richard Stanley!
Happy Birthday Ron Aharoni!
Nati’s Influence
Polymath and online research
The Polynomial Hirsch Conjecture: A proposal for Polymath3
Polymath 8 – a Success!
Polymath8: Bounded Gaps Between Primes
Mathematics, Science, and Blogs
Polymath1: Success!
Opinions
Chess can be a Game of Luck
Amy Triumphs* at the Shtetl
Test your intuition
Test Your Intuition (17): What does it Take to Win Tic-Tac-Toe
Mittag-Leffler Institute and Yale, Winter 2005; Test your intuition: Who Played the Piano?
Mathematics
The Amitsur-Levitzki Theorem for a Non Mathematician.
About Mathematics
Can Category Theory Serve as the Foundation of Mathematics?
Buffon’s Needle and the Perimeter of Planar Sets of Constant Width
A Few Mathematical Snapshots from India (ICM2010)
The Beauty of Mathematics
Science
Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
Itamar Pitowsky: Probability in Physics, Where does it Come From?
Riddles
Two Math Riddles
The Ultimate Riddle
Greg’s Dinosaurs Riddle
Discussions of various kinds
When It Rains It Pours
Why is mathematics possible?
Chomskian Linguistics (The phrase “more or less” in various languages)
News
The Kadison-Singer Conjecture has beed Proved by Adam Marcus, Dan Spielman, and Nikhil Srivastava
Francisco Santos Disproves the Hirsch Conjecture
Amazing: Peter Keevash Constructed General Steiner Systems and Designs
Exciting News on Three Dimensional Manifolds
Roth’s Theorem: Tom Sanders Reaches the Logarithmic Barrier
Greg Kuperberg: It is in NP to Tell if a Knot is Knotted! (under GRH!)
From Oberwolfach: The Topological Tverberg Conjecture is False
New Ramanujan Graphs!
Updates
Celebrations in Sweden and Norway
Mabruk Elon, India, and More
Teaching
A Proof by Induction with a Difficulty
In how many ways you can chose a committee of three students from a class of ten students?
MathOverflow related
Fundamental Examples
Why are Planar Graphs so Exceptional
Joel David Hamkins’ 1000th MO Answer is Coming
Joe’s 100th MO question
Gina says
My Book: “Gina Says,” Adventures in the Blogosphere String War
Anat Lotan: Who is Gina I
Anat Lotan: Who is Gina II, My Own Shocking Revelation
Praise For ‘Gina says’
Humor (?)
Believing that the Earth is Round When it Matters
Annotating Kimmo Eriksson’s Poem
Public service
Optimism – two quotes
The Simplified Pill Algorithm
Useful links
Stand Clear of The Closing Doors, Please
Combinatorics and more 