Recent content by GreyZephyr

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    Dilation generator in QM; Problem 3.1 in Ballentine

    Thank you for your help. That \mathbf{x}\in\mathbb{R}^3 was clear from the integral.
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    Dilation generator in QM; Problem 3.1 in Ballentine

    Thank you for the reply. It helped a lot though, I have a further question after expanding around $c$ i obtain a generator of the form -\frac{1}{2} -\mathbf{x}\cdot D where D is the differential operator. This then gives the commutator [U,P]=\mathbf{x}.DP+P\mathbf{x}D. and if we then choose...
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    Dilation generator in QM; Problem 3.1 in Ballentine

    I am working my way through Ballentine's Quantum Mechanics and I am stuck on the following problem. Homework Statement Problem 3.1 from Ballentine: Quantum Mechanics Space is invariant under the scale transformation x\to x'=e^cx where c is a parameter. The corresponding unitary...
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    What is a non-rectifiable bounded closed set in \mathbb{R}?

    I have come across fat cantor sets before and my problem was that I could not think of a closed set whose boundary had positive measure. As soon as you gave the hint the rest followed and I felt like a fool. Oh well such is the learning process. Thanks again for the help, I had been stuck on...
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    What is a non-rectifiable bounded closed set in \mathbb{R}?

    Thank you. I should have thought of that, but only considered the standard Cantor set. Thanks again.
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    What is a non-rectifiable bounded closed set in \mathbb{R}?

    Homework Statement I am trying to work my way through Analysis on manifolds by Munkres. Question 14.5 has me stumped. Any hints on how to tackle it would be appreciated. The question is: Find a bounded closed set in \mathbb{R} that is not rectifiable Homework Equations A subset S of...
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