### Archives

### Recent blog posts

- Prikry forcing may add a Souslin tree June 12, 2016
- The reflection principle $R_2$ May 20, 2016
- Prolific Souslin trees March 17, 2016
- Generalizations of Martin’s Axiom and the well-met condition January 11, 2015
- Many diamonds from just one January 6, 2015
- Happy new jewish year! September 24, 2014
- Square principles April 19, 2014
- Partitioning the club guessing January 22, 2014

### Keywords

20M14 Fodor-type reflection Fat stationary set Weakly compact cardinal Almost countably chromatic Foundations PFA(S)[S] Minimal Walks Selective Ultrafilter Successor of Singular Cardinal projective Boolean algebra L-space stationary reflection Generalized Clubs stationary hitting Forcing Axioms Singular Density Erdos-Hajnal graphs Ostaszewski square Stevo Todorcevic Nonspecial tree Luzin set Commutative cancellative semigroups Hindman's Theorem Knaster Cardinal function Kurepa Hypothesis Postprocessing function xbox Aronszajn tree Rock n' Roll Square-Brackets Partition Relations Partition Relations incompactness Chromatic number Diamond 11P99 PFA approachability ideal Almost Souslin Absoluteness Fast club Rainbow sets Club Guessing Antichain super-Souslin tree Uniformization Distributive tree polarized partition relation Axiom R Poset Souslin Tree weak diamond Slim tree very good scale Chang's conjecture Ascent Path HOD Reduced Power Singular coﬁnality square Dushnik-Miller Almost-disjoint famiy b-scale Whitehead Problem Sakurai's Bell inequality free Boolean algebra middle diamond Parameterized proxy principle Shelah's Strong Hypothesis Prevalent singular cardinals S-Space Universal Sequences Hereditarily Lindelöf space Mandelbrot set Successor of Regular Cardinal diamond star Jonsson cardinal Rado's conjecture Non-saturation Large Cardinals Martin's Axiom Constructible Universe Uniformly coherent sap Prikry-type forcing P-Ideal Dichotomy Coherent tree 05A17 Microscopic Approach Cohen real Cardinal Invariants coloring number Singular cardinals combinatorics Small forcing reflection principles tensor product graph weak square Forcing OCA Erdos Cardinal Hedetniemi's conjecture ccc square principles

# Tag Archives: Mandelbrot set

## A natural Mandelbrot set

Chris Hadfield is a Canadian astronaut, with a very high-profile twitter account. He posts there beautiful photos everyday, and I (plus half a million followers) enjoy it very much. Today, Chris posted the following picture: and I find it quite … Continue reading