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| bio | website | |
|---|---|---|
| location | ||
| age | ||
| visits | member for | 2 years, 8 months |
| seen | 4 hours ago | |
| stats | profile views | 114 |
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May 10 |
answered | Prove that the $2$ form defines a symplectic structure |
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May 9 |
comment |
integral of closed differential form What you have written is not true in general. Is there some other condition on $X$ which you've forgotten to mention? Is $X$ a closed manifold? |
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May 7 |
comment |
Proof that $(0,1)$ is connected. Your mistake is in the final sentence when you say "Since $A$ is closed, $A = \overline A$ and hence $s \in A$." We only know that $A$ is closed in $X$, but what you're claiming would require that $A$ be closed in $\mathbb R$ since the supremum $s$ only a priori exists in $\mathbb R$. |
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May 7 |
awarded | Caucus |
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Apr 20 |
comment |
If the inner product is symmetric iff $A=A^{T}$ Good job showing your work, but unfortunately you seem to be confused as to what it means for the inner product to be symmetric: it means that $\langle x,y \rangle = \langle y,x \rangle$ for all $x,y$, not that $\langle Ax,y \rangle = \langle x,Ay\rangle$. |
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Apr 5 |
revised |
Whats the connection between functions with curl 0 and holomorphic functions added 425 characters in body |
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Apr 5 |
answered | Whats the connection between functions with curl 0 and holomorphic functions |
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Apr 4 |
comment |
Why don't we study algebraic objects with more than two operations? Is the question: why don't we study algebraic objects with more than two operations as undergraduates, or do mathematicians in general study algebraic objects with more than two operations? |
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Apr 1 |
revised |
Confused about Eigenvectors added 76 characters in body |
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Apr 1 |
answered | Confused about Eigenvectors |
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Mar 30 |
answered | Need some help with a proof regarding vector spaces |
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Mar 30 |
comment |
Need some help with a proof regarding vector spaces @SchlomoSteinbergerstein, are you sure your explanation of the notation $[a]$ is correct? It looks like this should be related to cosets instead of linear combinations as you say. |
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Mar 19 |
answered | Let $\sigma,\tau \in S_n$. Prove that $\sigma \tau$ and $\tau \sigma $ have the same cycle type. |
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Mar 13 |
comment |
The multiplication of 2D vectors produces what? What's your definition of "vector multiplication"? |
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Mar 12 |
answered | Physics notation justified |
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Mar 9 |
comment |
How to show $f(x,y)=|xy|^\alpha\log(x^2+y^2)$ is differentiable at $(0,0)$? Can you first compute the partial derivatives at $(0,0)$? |
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Mar 9 |
comment |
Manifolds and Charts What's your definition of $S^n$ if not as a specific subset of $\mathbb R^{n+1}$? Before we can talk about having a manifold structure on a set, we need the actual set first. Saying that we want to construct manifolds without reference to an ambient space doesn't mean that the set itself shouldn't be defined using some ambient set, only that the manifold structure shouldn't be viewed as coming from a submanifold of an ambient manifold. |
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Mar 7 |
comment |
Understanding an Example of a Lie Groupoid Great answers. One more observation: if you identity $T^*G$ with $G \times \mathfrak g^*$ using your map $L$ and use this to transport the groupoid structure to one on $G \times \mathfrak g^* \rightrightarrows \mathfrak g^*$, you get nothing but the action groupoid for the coadjoint action of $G$ on $\mathfrak g^*$. |
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Mar 3 |
awarded | Fanatic |
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Feb 26 |
comment |
Orders of $g^2$ when $g$ is odd @IttayWeiss, the identity has order $1$. |
