# Questions tagged [conventions]

A convention is a set of agreed, stipulated, or generally accepted norms. It typically helps common efficiency or understanding but is not required, as opposed to a strict standard or protocol.

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### Are there several conventions (source or receiver) for the *Jones vector*? What about the one of particle physics?

There are several conventions for defining the polarisations left and right: from the source and from the receiver. See for example: https://en.wikipedia.org/wiki/Circular_polarization#...
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### Sign convention in optic problems

Note: The convention used in our physics textbook and the mentioned question is Cartesion Convention Today in our physics test, we were given the following question:- A mirror has focal length 20 cm ...
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### Definition for Fourier transform for physically representing field in frequency domain

If I have a time-dependent electric field $E(t)$ and want to calculate the spectrum of this field by $$A_0\cdot|E(\omega)|^2\,$$ where $A_0$ is some constant factor. My questions is which definition ...
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### Significant figures in textbooks

I know that there are a plenty of questions similiar to this one, but none of them was able to definitely give an answer, at least in my point of view. In so many Physics textbooks (Tipler, Halliday, ...
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### Wedge Product Convention

In Wald’s General Relativity textbook he defines the wedge product as: $$(w \wedge u)_{a_1 ... a_p b_1 ... b_q}= \frac{(p+q)!}{p!q!} w_{[a_1 ... a_p}u_{b_1 ... b_q]}$$ My question is relatively simple:...
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### Where must one use $x=A \cos \omega t$ and $x=A \sin \omega t$? [duplicate]

Consider the following example: A particle oscillates with simple harmonic motion in a straight line. In the first $t$ seconds, it travels a distance $a$. In the next $t$ seconds, it travels an ...
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### How do we Wick rotate the Maxwell $U(1)$ gauge theory's field strength $F$?

How do we Wick rotate the Maxwell $U(1)$ gauge theory's field strength, say in 3 space and 1 time dimensions? Suppose we start with a Lorentz signature with coordinates $(x_0, x_1, x_2, x_3)$, then we ...
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### $\gamma^5$ rotation of chiral fermion in (1) Peskin&Schroeder, (2) Weinberg, or (3) Srednicki

The theta angle due to the chiral gamma^5 rotation of chiral fermion results in the phase alpha(x) that has different + or - sign for (1) Peskin&Schroeder, (2) Weinberg or (3) Srednicki. Here ...
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### How to figure out if the vector product of force and displacement is $-\mathbf fd\mathbf x$ or $\mathbf fd\mathbf x$?

Consider the force due to a point charged particle at the origin and the particle which we move to also be charged with the same charge. When we move a particle from point $\mathbf{x}$(position vector)...
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