Recent content by Dahaka14

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    Entropy of Mixing for Two Ideal Gases at Different Temperatures

    Homework Statement Two monatomic ideal gases are separated in a container by an impermeable wall, with volumes V_{1} and V_{2}, temperatures T_{1} and T_{2}, number of atoms N_{1} and N_{2}, and both are at the same, constant pressure P. The wall is then removed, and the pressure is continued...
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    Is Z8 Isomorphic to Z4xZ2?

    Wow...\gcd(2,2)=2...awful. Sorry for wasting space.
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    Is Z8 Isomorphic to Z4xZ2?

    Homework Statement Show that \mathbb{Z}_{8} is not isomorphic to \mathbb{Z}_{4}\times\mathbb{Z}_{2}. Homework Equations \mathbb{Z}_{mn}\cong\mathbb{Z}_{m}\times\mathbb{Z}_{n}\iff \gcd(m,n)=1 The Attempt at a Solution I would say that since \gcd(4,2)\neq1, they are not isomorphic...
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    Expansion in a Small Parameter

    I double checked the expression, and it should be quadratic. Take a look at equation 7 on page 7 in the arxiv version http://arxiv.org/PS_cache/hep-ph/pdf/0002/0002108v3.pdf" . I took the inner product of the states and took absolute square, which has given me a large mess of terms. When I...
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    Expansion in a Small Parameter

    I know it's a general method, but the example that uses it and confuses me is in neutrino oscillation probabilities. In a paper, specifically [A. Cervera et al., Nucl. Phys. B579, 17 (2000)] and other papers that discuss probabilities which include CP-violation and matter effects, the...
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    Expansion in a Small Parameter

    When an expression is derived using an "expansion in small parameters," what do they generally mean? I am not too familiar with this term, and the only thing I can think of are Taylor expansions. I have seen expressions that contain functions of these parameters, and after the expansion in...
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    Normalized state vector for bosons, Shankar problem

    That makes sense. Thanks a lot!
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    Normalized state vector for bosons, Shankar problem

    Homework Statement Two identical bosons are found to be in states |\phi> and |\psi>. Write down the normalized state vector describing the system when <\phi|\psi>\neq0.Homework Equations The normalized state vector for two bosons with <\phi|\psi>=0, using the fact that...
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    Shankar One-Dimensional Problem

    Homework Statement Exercise 5.2.2 (b.) Prove the following theorem: Every attractive potential in one dimension has at least one bound state. Hint: Since V is attractive, if we define V(\infty)=0, it follows that V(x)=-|V(x)| for all x. To show that there exists a bound state with E<0...
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    Photodetachment Cross Section Formulas: Explained

    I know the formulas for the length and velocity forms of the photodetachment cross section for an electron with energy \hbar\omega are, respectively, \sigma_{L}(\omega)=\frac{4\pi^{2}\alpha a_{0}^{2}\omega}{3}\sum_{f}|\langle\Psi_{f}|\sum_{j=1}^{n}z_{j}|\Psi_{i}\rangle|^{2} and...
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    Differential Geometry Question

    The dot product should give \textbf{a}\cdot\textbf{t}=c\textbf{t}\cdot\textbf{t}=\frac{\textbf{t}\cdot\textbf{t}}{\sqrt{2}} I'm not sure where to go from here. The only thing that I have been able to think of is that perhaps the curve should be a helix, since a helix is such that...
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    Differential Geometry Question

    Homework Statement Find an explicit unit-speed non-degenerate space curve \vec{r}:(0,\infinity)\rightarrow\Re^{3} whose curvature and torsion \kappa,\tau:(0,\infinity)\rightarrow\Re are given by the functions \kappa(s)=\tau(s)=\frac{1}{s}. Homework Equations the only thing that I can think of...
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    Thought Experiment Involving Quantum Entanglement

    thanks guys, i REALLY understand it now, i know what's going on here i'm not just making stuff up to get jollies going, I'm planning on being a theoretical physicist myself, I'm majoring in math and physics, so I'm trying to be serious here, and a good physicist should be able to pick this...
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    Thought Experiment Involving Quantum Entanglement

    This doesn't refute my friend's thought experiment. Please tell me exactly which part of it breaks down in its argument for violation of special relativity. Also, I did not post it in that thread in fear of it getting pushed to the back of the discussion. I understand that no information is...
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