
Please post any and all homework or other textbookstyle problems in one of the Homework & Coursework Questions...

Feb2313 09:25 AM
micromass

1 
30,955 
Can someone please explain this to me.
Let X = fundamental group of a genus 2 surface
Let Y = fundamental group of...

Nov1409 06:49 PM
morphism

1 
1,668 
Hey,
Could anyone help some up briefly what it means if the fundemental group of a space X is trivial.
As i...

Nov1409 09:34 AM
rasmhop

1 
1,243 
I'm trying to find the equation of a curve in R3 where k=t=a/(s^2+b) where k is the curvature, t is the torsion and...

Aug2409 09:26 PM
Reb

1 
2,863 
I have this question from Nigel Hitchin's notes in PG:
"Let V be 3dimensional vector space with basis v1,v2,v3 and...

Sep409 03:42 AM
MathematicalPhysicist

1 
1,396 
How difficult is Spanier's Algebraic Topology text to understand? How about the exercises?

Aug2409 05:43 PM
wofsy

1 
3,078 
http://en.wikipedia.org/wiki/Jacobi_field
also see...

Aug2409 07:45 PM
Reb

1 
1,542 
how is discrete metric space given by d((x1,x2,....xn)(y1,y2,....yn))=0 if xi=yi else 1
...

Aug2409 08:03 AM
HallsofIvy

1 
1,453 
I'm trying do derive the vorticity equation
\begin{align}\frac{D\vec\omega}{Dt} &= \frac{\partial \vec...

Aug2509 10:10 PM
John Creighto

1 
1,351 
So, in my studies of math so far, we can take a certain geometry (or just any function) and analyze it, and ask...

Aug2909 04:07 PM
slider142

1 
1,009 
I am simply trying to understand why dS space has a signature (4+1) ?
Good old familiar Minkowski space is of course,...

Sep109 07:53 AM
George Jones

1 
1,073 
Hello,
for a game with friends I'm trying to determine a plausible geographical centre of a small country where I...

Sep409 03:04 PM
jim mcnamara

1 
1,111 
if a set A is both open and closed then it is R(set of real numbers) how we may show it in a proper way

Sep1009 02:36 PM
TacTics

1 
999 
Hi there,
Is there an "easy" way to find a tangent space at a specific point to an implicitly defined manifold? I...

Sep2809 12:56 PM
wofsy

1 
1,374 
D={z in C  z<1}
e: DxD > R by e(z,w)=(zw)/(1w'z) (here the w'=the conjugate of w, not sure how to insert a...

Oct309 03:44 PM
Matthollyw00d

1 
2,802 
P.S. This was supposed to go into the homework forum. I had windows open for both forums and I ended up using the...

Oct609 02:05 PM
wofsy

1 
3,312 
What is the orientation of the largest equilateral triangle contained within a square?

Oct709 01:45 AM
Hepth

1 
1,169 
What would be the euler angles of rotation 2pi/3 about the line x=y=z? If something were in the xy plane and it...

Jan110 04:49 PM
mnb96

1 
2,695 
I've read somewhere a proof of Gromov's nonsqueezing theorem using the fact that the action is a symplectic invariant...

Oct1009 03:31 PM
mma

1 
1,170 
I am not sure how to prove there is no Lebesgue number for an open cover {(1/n,1)} of interval (0,1). If I take any...

Oct1309 03:03 PM
lurflurf

1 
2,439 
Hi
how to find 3D point(lie on line) on the 3D line with given distance and from given 3D point(this is also lie...

Oct1409 12:35 AM
zhentil

1 
3,350 
Afternoon,
I'm studying Engineering Dynamics (4th Year Undergraduate) and I was wondering if anyone can point me to...

Oct1609 10:44 AM
tinytim

1 
1,093 
Hey guys, anyone know what the LaTeX code for the "cut" is? I've tried /lrcorner but that doesn't seem to be the right...

Oct1909 06:09 PM
tinytim

1 
1,375 
I am looking for some worked examples of calculating moment maps. I have to calculate some moment maps but have no...

Nov109 01:24 AM
mma

1 
1,561 
One of the exercises in the text I'm using for selfstudy asks to prove that the union of a pair of atlases A and B on...

Oct3009 06:58 PM
jojo12345

1 
944 
Dear all,
Studying for prelims, I would like to know the following. I attached the question as well(sorry).
Why do...

Nov1409 06:56 PM
morphism

1 
1,290 
Here is a similar one that again tells me that my undestanding of the notions is still not there. I would like to know...

Nov1109 07:35 PM
Hurkyl

1 
1,269 
The Apollonian Packing is generated by starting out with 3 mutually tangent circle and then using descartes theorem to...

Dec2609 03:14 PM
Gevalt

1 
2,446 
how do I show a topological space X with an order topology is regular. Ive shown it is hausdorff already.

Nov2309 05:44 PM
grief

1 
1,361 
So I'm trying to understand the statement: On a complex manifold with a hermitian metric the LeviCivita connection on...

Dec509 03:54 PM
cogito²

1 
2,261 
Let \theta be the angle between the diagonal of the unit cube in R^{n} and one of its axes.
Find
lim \theta (n)...

Dec1409 05:55 AM
Rasalhague

1 
1,273 
In calculus, the definition of the arc length of some curve C is the limit of the sum of the lengths of finitely many...

Dec2209 07:23 AM
wofsy

1 
1,810 
Let F = \left\{f :
Is F complete , under the given norm ?
My approach was to look at the pointwise limit of an...

Dec2409 11:42 PM
vineethbs

1 
2,747 
Why all two dimensional manifolds are conformally flat?
Why all manifolds with constant sectional curvature are...

Jan610 05:17 AM
wofsy

1 
1,741 
What can we tell about Lie group if we know its Lie algebra.
Let's consider the following example: we have three...

Jan1010 06:41 AM
Omega137

1 
1,240 
Hi,
I was given the following problem, and i couldn't solve it yet:
Give a bijection between the elements of...

Jan1210 09:23 AM
wofsy

1 
1,383 
Hello everyone,
While studying properties of Riemann and tensor and Killing vectors, I found this notation/concept...

Jan1410 05:47 PM
Ben Niehoff

1 
1,333 
Is there any difference to the meaning of these terms? I'm keep running across both of them.

Jan1610 02:39 AM
HallsofIvy

1 
1,147 
What is a question in topology asking of me when it says show that the topology of S1 and a quotient space agree?

Jan2010 09:14 AM
rasmhop

1 
1,019 
I'm self studying topology and so I don't have much direction, however I found this wonderful little pdf called...

Jan2010 09:27 PM
Fredrik

1 
3,365 
I am aware that a vector is a firstorder tensor, and that a secondorder tensor has nine components in threespace,...

Jan2310 04:42 PM
Vectronix

1 
1,222 