Reputation
1,692
Top tag
Next privilege 2,000 Rep.
Edit questions and answers
Badges
1 15 29
Impact
~60k people reached

  • 0 posts edited
  • 0 helpful flags
  • 387 votes cast
Jan
25
asked How did Von Neumann think of the formula for scalar product?
Jan
24
accepted Direct Sum and Intersection Query
Jan
22
asked Direct Sum and Intersection Query
Jan
19
accepted Good way of remembering Green's Theorem
Jan
19
asked Good way of remembering Green's Theorem
Jan
19
accepted No nontrivial cyclic modules imply module is simple?
Jan
19
asked No nontrivial cyclic modules imply module is simple?
Jan
15
answered Math blogs, pros and cons for writers?
Jan
11
comment Analytic Isomorphism from open region to upper half plane
Just to check, do you mean $f(z)=\frac{-2}{1+z}+1$?
Jan
5
comment Analytic Isomorphism from open region to upper half plane
Thanks for your help. Which topic of complex analysis should I read up to learn more of this?
Jan
5
accepted Analytic Isomorphism from open region to upper half plane
Jan
5
asked Analytic Isomorphism from open region to upper half plane
Jan
3
comment Hatcher Corollary 4.12
@MikeMiller No problem, thanks for your help
Jan
3
comment Hatcher Corollary 4.12
@MikeMiller Yes, I was saying the relative groups were automatically zero (due to the n-connectedness).
Jan
3
comment Hatcher Corollary 4.12
@MikeMiller What I deduced is since $(X,X^n)$ is n-connected, $\pi_n(X,X^n,x_0)=0$. Thus, applying the boundary map $\partial$ leads to $\pi_{n-1}(X^n,x_0)=0$. And so on, all the later terms are zero?
Jan
2
revised Hatcher Corollary 4.12
added 355 characters in body
Jan
2
asked Hatcher Corollary 4.12
Jan
2
comment Zeroth homotopy group: what exactly is it?
@Mauro I just read up: it is the set of two points at the end of a line segment
Jan
2
comment Zeroth homotopy group: what exactly is it?
@MarianoSuárez-Alvarez thanks for your answer! Why is $\pi_0$ not a group?
Jan
2
accepted Zeroth homotopy group: what exactly is it?