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dg.differentialgeometry
1h

revised 
geometric interpretation of Lie bracket
added 10 characters in body 
23h

comment 
How to numerically evaluate a integral whose limits are functions of x (using Gauss quadrature rule)?
I know what $\int_x^1 qdq$ means, but what would $\int_q^1 dq$ mean? 
1d

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AtiyahGuilleminSternberg Theorem for current
How do you define the moment map if the form is singular? Can you give an example of a Kahler manifold where the induced symplectic form is singular? 
1d

revised 
Random processes with smooth paths
added 92 characters in body 
1d

answered  Random processes with smooth paths 
2d

revised 
Nice way to express $H^{1}(\mathbb{S}^1)$
added 218 characters in body 
2d

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Nice way to express $H^{1}(\mathbb{S}^1)$
I'll add details to the answer. 
2d

answered  Nice way to express $H^{1}(\mathbb{S}^1)$ 
Apr
29 
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approximating smooth functions by nonsmooth ones, in the distribution topology
Firs, the space $\mathscr{D}$ is not a normed space so you cannot speak of the norms of linear functionals. From the definition of the topology on $\mathscr{D}'$ it follows that the operator $\frac{d}{dx}$ is continuous on $\mathscr{D}'$. For more details see L. Schwartz book on distributions. 
Apr
28 
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Can the topological algebra of analytic functions be endowed with a norm that defines the natural topology?
Can you define the "natural topology" on this algebra? 
Apr
26 
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Set of General Linear Position with Nonzero Measure
Can you define precisely the concept of general linear position? 
Apr
25 
revised 
Zeroes of global sections killed by differential operators
deleted 2 characters in body 
Apr
25 
answered  Zeroes of global sections killed by differential operators 
Apr
25 
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$p$adic Dirac measure as a weak limit
Set $B_{1/n}=\{x;\;\;x_p\leq 1/n\}$ set $v_n=\mu(B_{1/n})$, $\mu=$ Haar mesure, $\delta_n(x)=\frac{1}{v_n}I_{B_{1/n}}(x)$, where $I_A$ is the indicator function of a set $A$. 
Apr
25 
comment 
How to learn concepts of Functional Analysis which are common in PDE
The concept of weak topology/convergence is very well discussed in Chap.3 of Brezis' book. This will cover 99% of the situations you will encounter when investigating pdes. In fact I would recommend that you first read Brezis before you read more sophisticated discussions of spaces in duality. In particularly, I have not seen anywhere discussed so efficiently the direct method in the calculus of variations (Corollary 3.23 in Brezis). 
Apr
23 
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Recursively calculate the determinant
Don't worry about the meaning of $\otimes$. What I wrote is equivalent with your definition. My notreallyananswer makes two points: 1). it suffices to assume the matrices $\Sigma_{ii}$ are diagonal; 2) even the simplest case $p_1=\cdots =p_k=1$ is nontrivial. 
Apr
23 
revised 
Recursively calculate the determinant
added 1 character in body 
Apr
22 
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Why do people study representations of 3manifold groups into $SL(n,\mathbb{C})$?
What is the nice complete set of invariants supplied by the geometrization conjecture? What about the classification of knots and links? They are determined by their complements which are $3$manifolds with boundary. Deciding whether two knots are isotopic is still a very difficult problem. 
Apr
22 
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Constancy theorem for integral currents
In the above statement $A$ hast to be connected! Without this assumption the result is not true. 
Apr
22 
answered  Recursively calculate the determinant 