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comment The relation between the algebraic dimensions of a vector space and its dual
There are interesting things on this very similar MO question: mathoverflow.net/questions/13322/…
1d
answered The relation between the algebraic dimensions of a vector space and its dual
1d
asked Diffeomorphism-invariant spaces of smooth functions
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answered Looking for a “Guide for the Perplexed by Low-dimensional Topology”
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awarded  Informed
May
20
awarded  Civic Duty
May
18
awarded  Vox Populi
May
18
comment Herstein Problem No.7 Page 102
BTW, it's only partially relevant, but math.auckland.ac.nz/~obrien/research/gnu.pdf is a great read.
May
18
awarded  Suffrage
May
18
answered Finding the character table of this group
May
18
comment Does every uncountable subset of $\mathbb{R}$ have an uncountable closed subset?
I wouldn't like to bother you (that would be a very poor reward for your answer) but the Wikipedia article really frustrates me. What is your favourite reference for the existence of Bernstein sets?
May
18
comment Does every uncountable subset of $\mathbb{R}$ have an uncountable closed subset?
I don't know if I love your answer (because, objectively, it's perfect) or if I hate it (because I understand $\mathbb R$ a bit less now that I know that such beasts exist)... +1
May
18
comment Does every uncountable subset of $\mathbb{R}$ have an uncountable closed subset?
Note that general regularity properties imply that the answer is yes if $E$ contains a Lebesgue-measurable set $A \subset E$ of positive Lebesgue measure : en.wikipedia.org/wiki/Regularity_theorem_for_Lebesgue_measure (In particular, that works if $E = \mathbb R \setminus \mathbb Q$.) But your general question seems interesting.
May
18
comment Minimal polynomial of $\sqrt{2} + \sqrt{3}$ over $\Bbb{Q}(\sqrt{6})$
You have already proved that a degree two polynomial can cancel $\alpha$. So, either it is the minimal polynomial, or you can find a degree 1 polynomial which cancels $\alpha$. What would that imply on $\alpha$ ? Can you prove or disprove that $\alpha \in \mathbb Q(\sqrt 6)$ ?
May
18
answered What is the meaning of $\Omega^o_n$?
May
18
comment What is the meaning of $\Omega^o_n$?
I don't understand the question. Do you want to know the meaning of $\Omega_n^{O} = 0$ for some $n$ ? Do you want to know which manifold is the zero element is this group ? Do you want to know why there is a $O$ exponent in the notation? (which is a letter O, by the way, not a zero)
May
18
comment suppose $tr(A^k) = tr(B^k)$ for all $k$=$1,2,…$. why $A$ and $B$ are same characteristic polynomial? .
I must say I really dislike this "$M_n$" notation, which doesn't mention the field. (I have already seen it in this question: math.stackexchange.com/questions/1268459, whose style is somewhat comparable to the one at hand).
May
18
answered suppose $tr(A^k) = tr(B^k)$ for all $k$=$1,2,…$. why $A$ and $B$ are same characteristic polynomial? .
May
7
comment Isomorphic Designs
You could read this article www.ams.org/notices/200710/tx071001294p.pdf (some aspects of this article may be too complicated, but it's a survey). But I would really like to know which pair of nonisomorphic designs is the easier to construct "by hand". Apparently, there are 2 non isomorphic 2-(13, 3, 1)-designs [= (2,3,13)-Steiner system = STS(13)], but I won't try to construct and distinguish them by hand.
May
7
answered Reference for Affine Spaces