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# Category Archives: Guest blogger

## Stefan Steinerberger: The Ulam Sequence

This post is authored by Stefan Steinerberger. The Ulam sequence is defined by starting with 1,2 and then repeatedly adding the smallest integer that is (1) larger than the last element and (2) can be written as the sum of two … Continue reading

## Ehud Friedgut: Blissful ignorance and the Kahneman-Tversky paradox

Tversky, Kahneman, and Gili Bar-Hillel (WikiPedia). Taken by Maya Bar-Hillel at Stanford, summer 1979. The following post was kindly contributed by Ehud Friedgut. During the past week I’ve been reading, and greatly enjoying Daniel Kahneman’s brilliant book “Thinking fast … Continue reading

## Karim Adiprasito: Flag simplicial complexes and the non-revisiting path conjecture

This post is authored by Karim Adiprasito The past months have seen some exciting progress on diameter bounds for polytopes and polytopal complexes, both in the negative and in the positive direction. Jesus de Loera and Steve Klee described simplicial polytopes which are not … Continue reading

Posted in Convex polytopes, Guest blogger
Tagged Convex polytopes, Flag complexes, Hirsch conjecture, Karim Adiprasito
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## Eyal Sulganik: Towards a Theory of “Mathematical Accounting”

The following post was kindly contributed by Eyal Sulganik from IDC (Interdiciplinary Center) Herzliya. Eyal was motivated by our poll on certainty “beyond a reasonable doubt,” which is related to several issues in accounting. Mathematicians, I believe, are always looking … Continue reading

## Günter Ziegler: 1000$ from Beverly Hills for a Math Problem. (IPAM remote blogging.)

Scanned letter by Zadeh. (c) Günter M. Ziegler left-to-right: David Avis, Norman Zadeh, Oliver Friedmann, and Russ Caflish (IPAM director). Photo courtesy Eddie Kim. Update: The slides for Friedmann’s talk are now available. The conference schedule page contains now the slides for … Continue reading

Posted in Computer Science and Optimization, Conferences, Guest blogger
Tagged Linear programming
4 Comments

## János Pach: Guth and Katz’s Solution of Erdős’s Distinct Distances Problem

Click here for the most recent polymath3 research thread. Erdős and Pach celebrating another November day many years ago. The Wolf disguised as Little Red Riding Hood. Pach disguised as another Pach. This post is authored by János Pach A … Continue reading

Posted in Combinatorics, Geometry, Guest blogger, Open problems
Tagged Larry Guth, Nets Hawk Katz
13 Comments

## Anat Lotan: Who is Gina II, My Own Shocking Revelation

Who’s Gina? (Part 2): My Own Shocking Revelation By: Anat Lotan It was one of those typically hot Israeli end-of-August days; a scorching summer morning, where you have to convince yourself that the cool breezes of autumn are just around … Continue reading

## Michael Schapira: Internet Routing, Distributed Computation, Game Dynamics and Mechanism Design I

This post is authored by Michael Schapira. (It is the first in a series of two posts.) In this post, I’ll outline work on Internet routing and sketch important areas for future work, both on routing itself and, more broadly, on … Continue reading

Posted in Computer Science and Optimization, Economics, Guest blogger
Tagged incentive compatibility, Internet, Routing, Security
4 Comments

## Joe Malkevitch: Why Planar Graphs are so Exceptional

Not only do interesting questions arise by considering the special class of planar graphs but additional special issues arise when one considers a specific plane drawing of a planar graph. This is because when a graph is drawn in … Continue reading

Posted in Combinatorics, Guest blogger
6 Comments