Hey,
What is meant by Coulomb gauge not being Lorenz invariant?
The Coulomb gauge is just a constraint on \mathbf{A} and \phi and thus it is independent of inertial frame.
I posted the question in the wrong section. This question is in the context of QFT. The notes says:
A disadvantage of...
Hey, I have a short question.
The quantized field in Schrödinger picture is given by:
\hat{\phi} \left(\textbf{x}\right) =\int \frac{d^{3}p}{\left(2\pi\right)^3} \frac{1}{\sqrt{\omega_{2\textbf{p}}}}\left(\hat{a}_{\textbf{p}}e^{i\textbf{p} \cdot \textbf{x}} +...
So, the elements of \widehat{H} are given by \langle \psi_{a} | \widehat{H} | \psi_{b} \rangle with | \psi_{a} \rangle and | \psi_{b} \rangle are two basis vectors of the set (containing basis vectors) \left\{ | \psi_{k} \rangle \right\}. \langle \psi_{a} | \widehat{H} | \psi_{b} \rangle...
I have a question about operators in finite dimension Hilbert space.
I will describe the context before asking the question.
Assume we have two quantum states | \Psi_{1} \rangle and | \Psi_{2} \rangle .
Both of the quantum states are elements of the Hilbert space, thus | \Psi_{1} \rangle , |...
Hey, I have a question about proving Saha's equation for ionizing hydrogen atoms.
The formula is
\frac{P_{p}}{P_{H}} = \frac{k_{B} T}{P_{e}} \left(\frac{2\pi m_{e} k_{B}T}{h^2} \right)^{\frac{3}{2}}e^{\frac{-I}{k_{B} T}}
with
P_{p} pressure proton's,
P_{H} pressure hydrogen atoms,
m_{e}...
I have a question about a sentence in the book Introduction to Thermal Physics (Daniel v. Schroeder).
So in chapter 6, Schroeder talks about an atom isolated. This means its energy is fixed.
The atom is in some state. The energy states of the atom have degenerated. All microstates with that...
Hey, I have a question about the meaning of a variable in the Clausius-Clapeyron formula.
My textbook (Daniel v. Schroeder) says that the Clausius-Clapeyron formula is (for phase boundary between liquid and gas)
\frac{dP}{dT} = \frac{L}{T\left(V_{g} - V_{l} \right)} .
What is V_{l} or V_{g}...
Not, because the temperature of the system is not uniform (or equal). Is it possible to add heat in such a way that the process in quasistatic? In real life it is not possible but theoretically? Is the equation then valid?
Maybe I have to change my question. My question is what's is the use of...
I have a question about the Thermodynamic Identity.
The Thermodynamic Identity is given by
dU = TdS - PdV + \mu dN .
We assume that the volume V and that the number of particles N is constant.
Thus the Thermodynamic Identity becomes
dU = TdS .
Assume that we add heat to the system (we see that...
Hey, I have a really short question about electrostatics.
The boundary conditions are :
\mathbf{E}^{\perp }_{above} - \mathbf{E}^{\perp}_{below} = -\frac{\sigma}{\varepsilon_{0}}\mathbf{\hat{n}} ,
\mathbf{E}^{\parallel }_{above} = \mathbf{E}^{\parallel}_{below}.
My question is what is...
I have multiple questions about eigenstates and eigenvalues.
The Hilbert space is spanned by independent bases.
The textbook said that the eigenvectors of observable spans the Hilbert space.
Here comes the question.
Do the eigenvectors of multiple observables span the same Hilber space?
Here...
Hello, I have a question about the blue waves coming from sources S1 and S2 in de next picture.
The blue waves from sources S1 and S2, are those two resulting waves (interference of all wavelets, Huygens Principle) or are those blue waves two wavelets?
Good day,
I have a question about breaking an atom down in it's components.
For an example we have a neutral 4-helium atom. The helium atom have a nucleus which contains 2 protons and 2 neutrons. Around the nucleus of the helium atom 2 electron orbits in the k-shell (according to Bohr's...