bio  website  

location  
age  
visits  member for  5 years, 10 months 
seen  13 hours ago  
stats  profile views  815 
1d

comment 
Which polynomial's roots are its coefficients?
Lubin's suggestion gives a continuous map, which is nice. The process outlined here can't be made continuous (e.g. to define it for $z^2 + e^{i\theta}$ you essentially have to choose branches of the square root function for the coefficients). On its own, that seems unnatural, but it makes sense as picking a branch of the inverse of Lubin's map. Igor's idea of looking at all permutations then corresponds to taking the full inverse. 
Sep
1 
awarded  Guru 
Aug
30 
comment 
Is $\mathbb{R}^3 \setminus \mathbb{Q}^3$ simply connected?
Is it obvious that transversality arguments work for weird nondifferentiable curves? In a manifold you know any curve is homotopic to a differentiable one, but showing that fact in $\mathbb{R}^3 \setminus \mathbb{Q}^3$ doesn't seem any easier than the original question. 
Aug
30 
awarded  Good Answer 
Aug
30 
awarded  Enlightened 
Aug
29 
comment 
Is $\mathbb{R}^3 \setminus \mathbb{Q}^3$ simply connected?
@Victor The argument takes for granted that the ambient space stays simply connected (even connected) when you remove just a finite set of pointsfine in $\mathbb{R}^3$ but not $\mathbb{R}$ or $\mathbb{R}^2$. 
Aug
29 
awarded  Nice Answer 
Aug
29 
answered  Is $\mathbb{R}^3 \setminus \mathbb{Q}^3$ simply connected? 
May
26 
comment 
John Nash's Mathematical Legacy
It's amazingly prescient, from a computer science perspective. Here's a link to the paper: rand.org/content/dam/rand/pubs/research_memoranda/2008/… 
Apr
15 
awarded  Nice Answer 
Apr
9 
answered  Deep Learning / Deep neural nets for mathematician 
Mar
11 
comment 
understanding the average height of a unit hypersemisphere
On a highdimensional sphere most of the mass is concentrated around the equator, where the height is lowest. That's a heuristic explanation for why the average height goes to zero. 
Feb
22 
reviewed  Approve Is the Ford disk packing optimal? 
Feb
2 
comment 
What's the variance in the Six Degrees model?
This is one classic paper on the search problem: cs.cornell.edu/home/kleinber/swn.pdf ... and in general it's a good entry point into the literature. 
Jan
1 
revised 
Foliation with leaves which are and are not dense
better wording 
Jan
1 
revised 
Foliation with leaves which are and are not dense
fixed typo 
Jan
1 
answered  Foliation with leaves which are and are not dense 
Nov
23 
awarded  Enlightened 
Nov
23 
awarded  Nice Answer 
Nov
23 
revised 
How large can you draw an island on a map?
added note about computability 