Recent content by philipp_w

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    Transformation of random variable

    Do you know any source e.g. textbook which treats this more general problem? I would like to consider the Lesbegue integral, where this differentiation technique finally reaches its boundaries ;)
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    Transformation of random variable

    I think I got it now, let us try to formalize this a bit: We only consider absolutely continuous RV, but will use the Riemann integral for simplicity. Let ##I \subseteq ℝ## be an open interval and X be an RV with ##X \colon \Omega \to I## of continuous type. Let ##\Phi \colon I \to J## be...
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    Transformation of random variable

    I will try to follow your notation: Your treatments ended with the result P(U \leq u ) = G(u) = F(h^{-1}(u)) But only if I knew in advance that P(U \leq u) is of continuous type, meaning that P_{U} \ll \mathbf{\lambda}, where ##P_{U}## is the image measure of the probability measure...
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    Transformation of random variable

    Hi there, I am currently reading Rohatgi's book "An introduction to probabilty and statistics" (http://books.google.de/books?id=IMbVyKoZRh8C&lpg=PP1&hl=de&pg=PA62#v=onepage&q&f=true). My questions concerns the "technique" of finding the PDF of a transformed random varibale Y by a function...
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    Field Operators in Klein-Gordon theory

    thats my problem
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    Field Operators in Klein-Gordon theory

    Am I right in the assumption that this is a sort of some natural requirement to those field operators fullfiling the equations of motions? Because since we started with our intuitive wave-partivle thinking from the Schrödinger theory to predict a relativistic wave equation, we got stucked in...
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    Field Operators in Klein-Gordon theory

    Currently I am working through a script concerning QFT. To introduce the concept of canonical filed quantisation one starts with the (complex valued) Klein-Gordon field. I think the conept of quantising fields is clear to me but I am not sure if one can claim that the equations of motion for the...
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    Why Irreducibel Representations?

    But this sounds more like a definition to me, something grown out of experience or being a convention. I hope that I am right in thinking of irreducible representations as the fundamental object for any representation(?) And that is the reason for looking such structures if we are doing...
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    Why Irreducibel Representations?

    so to understand you right; the reason to look for irred.reps (in physics!) is just something according to their great (mathematical) properties...theres nothing like a 1:1 correspondance in nature that allows us only to look for irreducibel reps. It is sometimes tricky in physics to find out...
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    Why Irreducibel Representations?

    Hallo, I would like to know why physicists are always seeking for irreducible representation of a given group. I know that a reducible one is decomposable into irreducible representations (under special circumstances), but what is the physical motivation that irreducible reps are fundamental...
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    Homotopy classes appendix in Weinberg's QFT book, Part I

    hi, i am also trying to do the same as you do. but I got stucked on the formula (2.B.7). It seems that you have the answer, could you please provide me with that one. I am not sure what is really done to achieve this result in (2.B.7). greets - philipp
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    What is the Gelfand representation theory for Banach algebras?

    surjective? I would like to know why the Gelfand transform in the case of a commutative, unital Banach Algebra is isomorphic to a SUBalgebra on C(Omega). So why is the gelfand transform a function "into" C(Omega)? Why does the Gelfand transform not reach all continuous functions which can be...
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