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Tagged with normalizationmomentum
10 questions
1vote
2answers
136views
Changing the basis from $p$-basis to $k$-basis in standard quantum mechanics
if $$\hat p = \int dp |p\rangle p \langle p|$$ and I want to chage the basis to $|k\rangle$ it is correct to say that $\hat p$ is therefore equal to: $$ \hat p = \hbar^2 \int dk |k\rangle k \langle k| ...
1vote
0answers
131views
Weinberg's normalization convention for momentum eigenstates
In this answer https://physics.stackexchange.com/a/376193/274751 two different conventions for the normalization of momentum eigenstates are mentioned. This convention amounts to the choice of $N(p)$ ...
0votes
2answers
605views
Defined Momentum vs. Defined $k$
In quantum mechanics usually we write the momentum operator $\hat{p}$ as: $$\hat{p} = \hbar \hat{k}. \tag{1}$$ with of course: $$\hat{p}|p\rangle = p |p\rangle \tag{2}$$ $$\hat{k}|k\rangle=k|k\rangle \...
- 4,683
6votes
1answer
1kviews
Weinberg QFT 1 Normalization one 1 particle states p. 66
I encounter a question regarding the derivation of the normalization of 1 Particle states in Weinbergs book (Formula 2.5.14). Similar questions were asked in A question on page 65 of Weinberg's ...
- 450
4votes
3answers
1kviews
Can momentum never be zero in quantum mechanics?
I have seen Zetilli's QM book deals with $E>V$ and $E< V$ (tunnelling) in case of the potential wells deliberately avoiding the E=V case, so I thought maybe something is intriguing about this ...
- 1,108
1vote
1answer
175views
Should a wavefunction in momentum space be normalisable?
Is this a condition that the wavefunction in momentum space should be normalizable? Like we said that a particle has to be between ${-\infty}$ to ${\infty}$. Will the same argument also work for ...
0votes
1answer
826views
Wave-Function Normalization in Momentum Space Not Possible
Hello, I just have a question about this passage; specifically, I do not understand why the result of the inner product (the integral of u_k* and u_k') being the delta function defies conventional ...
0votes
1answer
193views
Confusion in normalization of position space and momentum space
It seems that in LSZ formalism approach, or just Feynman diagram approach, we can compute scattering amplitude of $\langle x_{out} | y_{in}\rangle$ (position space) and $\langle p_{out} | p_{in}\...
- 327
0votes
1answer
548views
Inner product of standard-momentum one-particle states in Weinberg
My question has essentially already been addressed in Questions concerning some parts of the section on one-particle states in Weinberg's first volume on QFT (third question), but unfortunately ...
- 633
4votes
1answer
714views
A question on page 65 of Weinberg's QFT volume 1
The equation (2.5.12) on page 65 says that: $$ \left(\boldsymbol{\Psi}_{k',\sigma'},\boldsymbol{\Psi}_{k,\sigma}\right)=\delta^3\left(\boldsymbol{k}'-\boldsymbol{k}\right)\delta_{\sigma '\sigma}. $$ I ...
