All Questions
Tagged with terminology field-theory
49
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What is the difference between field and disturbance?
In my textbook Sears & Zemansky's University Physics, 15th ed, Page-399, it is written that,
"A useful way to describe forces that act at a distance is in terms of a field. One object sets ...
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What is the difference between wavefunction renormalization and field strength renormalization?
A while ago I asked a question asking what is field strength renormalization (What exactly is field strength renormalization?). I now have a better way of thinking about this, which is that it relates ...
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When does a theory decouple?
The question is very broad, but it seems to me that the term 'to decouple' is also used in various contexts. For example, neutrinos decouple from the photons in the early Universe, when the ...
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What exactly is field strength renormalization?
One thing I have not fully understood is what field strength renormalization is. In Peskin & Schroeder's book "An Introduction to Quantum Field Theory" (Section 7.1) they introduce it as ...
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What is the difference between electromagnetic wave and electromagnetic field? [closed]
I am confused about the difference between electromagnetic waves and electromagnetic fields. Can you please explain the distinction between the two and how they relate to each other?
user356659
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Gauge symmetry and Gauge Transforms
In QFT or CFT, say the action is invariant under some local transformation. Can we call that transformation a Gauge transform?
There is a specific notion of gauge transform in math which is defined as ...
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Are mediums fields?
I understand that, at the more fundamental physical level, waves are phenomena of Fields. Like electromagnetic waves of the electromagnetic field.
However, I also know that we can have waves in ...
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"Classical field configuration" - QFT
I often encounter the term "classical field configuration" in the scope of QFT, but I have a hard time interpreting what it really means.
If I understood it correctly, then a general field ...
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Why do excitations not exist in non-quantum fields? [duplicate]
In my understanding, where the value of a quantum field [i.e. a field with discrete values] is 0 it is said to be in the ground state, and where it is not 0 it is said to be an excitation. Why do we ...
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What does it mean "to smear an operator" in QFT?
If possible, try to keep it physical (not too mathy). If I'm right, this smearing is necessary to determine the position of a particle in QFT. Why is that necessary? And please, spare my poor soul ...
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Conserved quantity from a conserved current
In my QFT course, it was asserted that the conserved quantity associated with some conserved current is given by $Q = \int_v j^0d^3x$ where $j^0$ is the time component of the conserved current, and $d^...
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Why don't we call gravitational field as acceleration since both of these quantities are Force/mass?
We know that gravitational field is given by the formula $F/m$; where $F$ is gravitational force and $m$ is the unit mass that we are using to calculate the field.
But we also know that $F/m$ is ...
user297610
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What is the relationship between 'taste' and 'flavor' in particle physics?
This paper, among others, discusses 'taste symmetry.' What is it talking about, and how does it relate to flavor?
Reference: Borsanyi, S., Fodor, Z., Guenther, J.N. et al. Leading hadronic ...
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Is this the most general form for a gauge transformation?
From my understanding, a gauge transformation in QFT is a local transformation in the fields under which the action is invariant. I usually write it, for a theory with scalars, fermions, and vector ...
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What is the difference between "field equations" and "equations of motion"?
I come across the terms "equations of motion" and "field equations" all the time, but what is the difference? For example, general relativity is described in terms of the Einstein ...
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