Recent content by simpleton1

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    MHB Help with functional analysis questions

    Hi, I tried to translate the question as much I could but possibly something got lost on the way. The definition of the measure is that if a group or set (the professor called it group, possibly he meant a set) is bound the measure is 0 and if its complement is bound the measure is 1...
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    MHB Help with functional analysis questions

    Some more thoughts : 3. Define Xn a series in ${C}^{n}$ that weakly converges to X , Therefore for every Y in ${C}^{n}$ : $$\lim_{{k}\to{\infty}}<{X}_{k},Y>=\lim_{{k}\to{\infty}}\sum_{i=1}^{n}<{{X}_{k,i}},{Y}_{i}>=\sum_{i=1}^{n}<{{X}_{i}},{Y}_{i}>$$ We need to prove that $$...
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    MHB Help with functional analysis questions

    1. a. For every group in A , its complement is also in A. Every subgroup of a bound group is also bound. Using this and the de-morgan rules show that A is closed for intersection, not and finite union. A is not closed for infinite union because infinite (even countable) union of...
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    MHB Help with functional analysis questions

    Hi, Could someone post a solution to the following questions : 1. Let R be the real numbers and A a collection of all groups that are either bound or their complement is bound. a. Show that A is an Algebra. Is it a sigma algebra? b. Define measure m by m(B) = {0 , max(on B) x <...
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    MHB Help for test - functional analysis

    Ok, Thanks. I got the first two questions and the first part of question 3. But the second part of 3 has still got me confused - since the number of elements in a different than 0 are finite , the sum of $\left\lVert{a}\right\rVert\infty$ over a=(1,1,1,1,...0,0,0) will not be $\infty$ but a...
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    MHB Help for test - functional analysis

    Re: help for test - functional analysis\mu Hi Euge - thanks for the commentation. I did post the questions under the influence of tiredness. :D I've fixed most things I think. You are right about the definition of L in question 3. I just got too lazy to Latex it.
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    MHB Help for test - functional analysis

    Hi - my professor in functional analysis posted 4 prior years tests just 4 days before the test without solutions. I'd appreciate if anyone can help send solutions for the following with the following questions : 1. $\mu$ is a sigma additive measure over sigma algebra $\Sigma$. A $\in...
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    MHB What is a Semigroup and How Does it Relate to Immeasurable Sets?

    Also might help me solve this is if the compliment of an immeasureable group is measureable. Or if the combination of a measureable or immeasureable function is immeasureable. Can any of these be proven?
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    MHB What is a Semigroup and How Does it Relate to Immeasurable Sets?

    I tried to ask the professor but he also didn't understand the question. We didn't learn about semi-groups in this course. Could you please try and solve under reasonable assumptions?
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    MHB What is a Semigroup and How Does it Relate to Immeasurable Sets?

    Perhaps what is missing is that in this course when they say immeasureable it means immeasureable by the lebesgue measure. I would copy the question text directly but it's not in english so I just translated it.
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    MHB What is a Semigroup and How Does it Relate to Immeasurable Sets?

    All it says is that E is an immeasureable group contained in (0,1).
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    MHB What is a Semigroup and How Does it Relate to Immeasurable Sets?

    Thanks again for your help. About 1 - I'm still not sure how it can be that the triangle inequality holds since $$(\sum_{n=0}^{\infty}{(P+Q)}^{2}\left(\frac{1}{2}\right)^{\!{n}})^{1/2}>\left\lVert{P+Q}\right\rVert$$ for polynomes. About 2 - I didn't write the question in part a...
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    MHB What is a Semigroup and How Does it Relate to Immeasurable Sets?

    Thank you very much! Since you've been so helpful I want to ask two additional, simpler questions (hope I got the notation right) : 1. $$\left\lVert{P}\right\rVert = (\sum_{n=0}^{\infty} {P}^{2} (\left(\frac{1}{2}\right)^{\!{n}}))^\frac{1}{2}$$ where P is a polynomial defined over...
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    MHB What is a Semigroup and How Does it Relate to Immeasurable Sets?

    Hi, I'm taking a course in functional analysis and having some trouble with the following questions : 1. L1(R) is the space of absolutely integrable functions on R with the norm integrate(abs(f(x)) over -inf to +inf. Define a linear operator from L1(R) to L1(R) as A(f)(x)=integrate...
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