# Questions tagged [notation]

The tag has no usage guidance.

924 questions
Filter by
Sorted by
Tagged with
99 views

74 views

### How to differentiate Capacitance (Italized C) and Coloumbs (regular C) on paper [closed]

I am doing a question on capacitance and coulombs. I got the answer correct, but I was wondering how a physicist, when doing the calculation on paper, would differentiate a C and C?
113 views

191 views

63 views

### Moment of Inertia equation for small volume

Below is the equation of the moment of inertia for small volume elements, $\Delta m$ $$I = \lim_{\Delta m_i \to 0} \sum_{i} r^2_i \Delta m_i = \int r^2 dm$$ Can someone please explain it to me on ...
146 views

### Identities from ket to bra vector

I have three questions. Lets say I have a state $\lvert\psi\rangle = \hat{c}_1^\dagger \lvert 0 \rangle$. Is the corresponding bra then given by $\langle\psi\lvert= \hat{c}_1 \langle 0\lvert$ ? ...
325 views

### Inner product in QFT

When we write inner product in QM for example $\langle\psi\rvert x \psi\rangle$it means (in position space) $\int\psi^*(x,t)x\psi(x,t)dx$. But when we write, in QFT, $\langle0\rvert0\rangle=1$ what ...
47 views

305 views

86 views

332 views

### In quantum mechanics, is $|\psi\rangle$ equal to $\psi(x)$?

So I'm going through my notes and I think I've confused myself. We often imply $$|\psi\rangle \to \psi(x)\\ \langle\psi| \to \psi(x)^*$$ for instance when we talk about eigenvalue equations we ...
162 views

### A question about the notation of the Standard model

The ${\rm SU(2)_L}$ doublets, for example, the left-handed quark doublets $Q_{iL}\equiv(u_{iL}, d_{iL})^T$ are assigned quantum numbers $(\textbf{3},\textbf{2})_{+1/6}$, which means $Q_{iL}$ are ...
73 views

### Notation issue for mixed tensors

When I am asked to evaluate, $\mathbf{U^{\alpha}_{~,~~\beta}}$ for all $\alpha$ and $\beta$, what does it mean? I have not able to understand this notation. In case of $\mathbf{g(~~,~\bar{A})}$ I ...
392 views