Recent content by cristianbahena

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    Looking for a Book on Relativistic Quantum Mechanics with One-Forms?

    hi! Do you know about a good book that introduces relativistic quantum mechanics with one-forms (diferential forms) like the book a first course of general relativity of Schutz does?
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    LaTeX Advantages and disadvantages of VIM-LaTeX

    advantages and disadvantages of VIM-LaTeX?
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    The concept of a force lifting a weight and the work done

    if I apply a force constant F=100N en ##y## direction to a body of mass 2kg, it is elevated 3m and I know that the force of gravity is in ##y## direction too. What is the work that I did? I think: ##W_{me}=(F_{me}-F_{g})\times 3## it is correct? and the work made by gravity is "0".
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    I Gauss' Theorem -- Why two different notations are used?

    Usually un physics triple or double integrals $$\int \int$$ $$\int \int \int$$ Are changed by only one simbol $$\int$$, so that is the same equation. The simbol $$\partial v$$ means that the integral Is computed on boundary superfice of $$v$$ or on boundary of $$v$$. $$\partial v=S$$
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    I How Does the Rotation Operator Affect Spin in Quantum Mechanics?

    i know that $$S_z |+ >= \frac{\hbar}{2} |+ >$$ also $$ D_z(\phi)= 1+i\frac{S_z}{\hbar}\phi$$ operator of infinitesimal rotations, if we apply this operator $$n$$ times: $$ (D_z(\phi))^n= (1+i\frac{S_z}{\hbar}\frac{\phi}{n})^n$$ in the limit $$ lim_{n\rightarrow \infty}(D_z(\phi))^n=...
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    I How Does the Rotation Operator Affect Spin in Quantum Mechanics?

    sorry! for compute: $$e^{\frac{iS_z\phi}{\hbar}}S_ x e^{\frac{-iS_z\phi}{\hbar}}$$ so, if we use $$S_x=(\frac{\hbar}{2})[(|+><-|)+(|-><+|)]$$ $$e^{\frac{iS_z\phi}{\hbar}}(\frac{\hbar}{2})[(|+><-|)+(|-><+|)] e^{\frac{-iS_z\phi}{\hbar}}$$ so, why that is equal to...
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    I How Does the Rotation Operator Affect Spin in Quantum Mechanics?

    for compute: $$e^{\frac{iS_z\phi}{\hbar}}S_x e^{\frac{-iS_z\phi}{\hbar}}$$ so, if we use $$S_x=(\frac{\hbar}{2})[(|+><-|)+(|-><+|)]$$ $$e^{\frac{iS_z\phi}{\hbar}}(\frac{\hbar}{2})[(|+><-|)+(|-><+|)] e^{\frac{-iS_z\phi}{\hbar}}$$ so, why that is equal to...
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    Relativity What's the best book to learn general relativity?

    What is the best book to learn general relativity for undergraduate and graduate students ? And why?
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    A What are local and non-local operators in QM?

    When F(r)= r One get: $${A \phi}(r)= r \phi{r}(r)$$ its a eigenvalue equation when $$f(r)= -i \hbar \partial_r$$ One get: $${A \phi}(r)= -i \hbar \partial_r \phi{r}(r)$$ it has no sense. is the why is local or no local am i right? Note: i´m using $$A\phi (r)= \int dr´\phi(r) \alpha(r-r´)...
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    A What are local and non-local operators in QM?

    In Hartree-Fock method, I saw the Fock operator has two integrals: Coulomb integral and exchange integral. One can define two operator. "The exchange operator is no local operator" why? Whats de diference: local and no local operator? And why do the operators have singularities? thanks
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    I Why Does div[grad(1/r)] Equal -4πδ(r vec)?

    I don't understand why grad(1/r)= (-1/r^2)ê_r. I know its derivate, but in cero the function is not definite and you can't find its derivative in cero.And, why div [grad(1/r)]=-4πδ(r vec) ?
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