Tagged Questions

6
votes
0answers
203 views

Does an isomorphism between infinitesimal neighbourhoods induce a jet of a diffeomorphism?

Let $D$ be a divisor in a (compact) Kahler manifold $X$. Let $N$ be the total space of the normal bundle of $D$ in $X$ and identify $D$ with the zero section of $N$. Let $m\subset …
7
votes
4answers
2k views

Is there a simple way to compute the number of ways to write a positive integer as the sum of three squares?

It's a standard theorem that the number of ways to write a positive integer N as the sum of two squares is given by four times the difference between its number of divisors which a …
4
votes
0answers
1k views

Good textbooks on probability and/or stochastic processes, emphasizing simulation

Any recommendations for textbooks on probability and/or stochastic processes that emphasize simulation? I'll be teaching this course in the Fall.
-1
votes
0answers
222 views

chinese remainder theorem (euclidean Algo vs chinese algo) [closed]

I am wondering that what is the difference between the ways of finding unity using euclidean algo and the chinese way of finding it!????
1
vote
2answers
273 views

What is the stadium curve, and how differentiable is it?

What is the definition of a stadium curve and does it have a curvature that is defined and continuous at each of its points?
3
votes
1answer
298 views

To what extent can one get rid of tangent lines and still have a continuous surface?

Does there exist in Euclidean 3-dimensional space R^3 a continuous 2-dimensional surface S specified by an equation of the form z-F(x,y) which satisfies the following conditions? …
3
votes
2answers
1k views

Is there a nice expression for the number of lattice points on a sphere? [closed]

Possible Duplicate: Is there a simple way to compute the number of ways to write a positive integer as the sum of three squares? Is there a nice expression for the number …
0
votes
5answers
853 views

Interview Question [closed]

Possible Duplicate: solving f(f(x))=g(x) Here is a nice interview question for computer science people: Write a unary function f such that f(f(x)) = -x Constraints: T …
1
vote
1answer
347 views

What is the partial derivative in this expression?

The question is similar to this one http://mathoverflow.net/questions/22523/implicit-derivative Let $x_1, x_2, x_3$ be three points in $\mathbb{R}^3$, $A=(a_{ij})$ is a $3\times 3 …
8
votes
1answer
900 views

P-adic local Langlands for non-unitary representations?

In Colmez's work on the p-adic local Langlands correspondence for ${\rm GL}_2(\mathbb{Q}_p)$, he works with ${\rm GL}_2(\mathbb{Q}_p)$-representations on $p$-adic Banach spaces whi …
3
votes
2answers
2k views

triangulations of torus, general, and Euler number. (Hopefully more interesting/relevant)

Hi, everyone: I have been going over some simplicial homology recently, hoping to get some geometric insight that I don't know how to get from the algebraic machinery alone. …
28
votes
1answer
2k views

Finiteness property of automorphism scheme

Some time ago I mentioned a certain open question in an MO answer, and Pete Clark suggesting posting the question on its own. OK, so here it is: First, the setup. Let $X$ be a pr …
2
votes
1answer
439 views

Ultrafilters containing a principal filter

If X is a set and A is a subset of X containing at least two elements, then certainly for any element $a \in A$, the principal ultrafilter of $a$ contains the principal filter of A …
16
votes
5answers
1k views

Compactification theorem for differentiable manifolds ?

Just parallelling this question, that seemed not to admit an easy answer at all, let's "soft down" the category and ask the same thing in the case of $\mathcal{C}^{\infty}$-differe …
5
votes
2answers
1k views

Can I relate the L1 norm of a function to its Fourier expansion?

I would like to express the integral of the absolute value of a real-valued function $f$ (over a finite interval) in terms of the Fourier coefficients of $f$. Failing that, I would …

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