12,437 reputation
11341
bio website mypage.iu.edu/~necolema
location Indiana
age 26
visits member for 3 years
seen 31 mins ago

"Arithmetic is the hardest of the sciences, this is well-known." -V. Touraev

Comathematician: A device for turning cotheorems into ffee.


Sep
18
awarded  Yearling
Sep
4
comment Path-connected, simply connected subsets of $\mathbb{R}^n$
How about $[0,1]\times[0,1]$ and $[0,1]\times\{0\}$?
Aug
31
awarded  Nice Answer
Aug
25
comment Strange question about magnetic dipole in a plane at infinite distance
You would probably get a better physical answer at physics.stackexchange.com
Aug
15
revised Prove $\sin^{2m}\alpha\cdot\cos^{2n}\alpha\leq\frac{m^m n^n}{(m+n)^{(m+n)}}$
added \ to sines and cosines
Aug
12
awarded  Generalist
Aug
6
comment Exponential equation: $2e^{-x} - e^{-2x}=0.$
OK, I see. Thanks.
Aug
6
comment Exponential equation: $2e^{-x} - e^{-2x}=0.$
What is the question?
Aug
6
comment Fibre is open in covering space
The fiber is not open in the cover, but each point in the fiber is open in the fiber.
Aug
6
answered Fibre is open in covering space
Jul
27
answered Differential of rotation matrix at the north pole of sphere
Jul
27
comment Differential of rotation matrix at the north pole of sphere
What have you done to try to compute it? Where did you run into difficulty?
Jul
27
comment Differential of rotation matrix at the north pole of sphere
What's the question?
Jul
26
answered Show that a star convex set $X \subset \mathbb{R^n}$ is simply connected.
Jul
20
comment Differential Forms on submanifolds
Dear @GeorgesElencwajg Thank you for your suggestion. Does this edit appear a better explanation?
Jul
20
revised Differential Forms on submanifolds
added 1210 characters in body
Jul
19
comment Embedding of $\mathbb{R}^2 \to \mathbb{R}^3$ with non-parallel tangent planes
I would start by surveying the common embeddings (e.g. graphs or level sets of common functions) to see if any of them satisfy the criterion.
Jul
19
comment Differential Forms on submanifolds
Dear @GeorgesElencwajg I do not follow this last point: if $\omega$ is a $p$-form on a submanifold $M$ of $\mathbb{R}^n$, define $\hat{\omega}$ on the tangent bundle of $M$ in $\mathbb{R}^n$ by the rule that $\hat{\omega}$ on $TM$ is $\omega$ and $\hat{\omega}$ on the normal bundle is zero. Since any vector decomposes into a sum of normal and tangent vectors, $v=v^n + v^t$, then $\hat{\omega}(v_1,\ldots,v_p) = \hat{\omega}(v_1^n,\ldots,v_p^n) + \hat{\omega}(v_1^t,\ldots,v_p^t)$ seems a perfectly well-defined $p$-form to me. Though perhaps I have not yet had enough coffee this morning.
Jul
18
answered Differential Forms on submanifolds
Jul
10
awarded  general-topology