Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [terminology]

Use this for questions relating to the proper use of physics terminology or nomenclature.

12
votes
0answers
372 views

Gauge invariant but not gauge covariant regularization

I'm not sure if someone's already asked this before, but I was wondering, in field theory, when we say that a certain field is gauge invariant but not gauge covariant, what does this mean? In ...
10
votes
0answers
459 views

Who invented the term “Coulomb logarithm”?

Who is the author of the term "Coulomb logarithm"? In fact, Coulomb logarithm was computed by Langmuir in his paper of 1928 where the term "plasma" was introduced into physics, but the term "Coulomb ...
6
votes
0answers
252 views

Physical interpretation: weighted eigenvalues of the Laplacian with a potential

I'm a mathematician with only the basic knowledge of Physics, so my question may be trivial: in this case, mercy me. :-) Let $\Omega \subseteq \mathbb{R}^N$ be a domain and let $V,m:\Omega \to \...
4
votes
0answers
68 views

When was the phrase “beta function” of renormalization first used?

My question is a historical one: when was the phrase "beta function", as it pertains to the renormalization-group equations, used in physics? I am talking about this beta function: $$\beta_g\equiv \...
4
votes
0answers
145 views

Is the phrase “coupling constant” interchangable with “ strength of interactions”?

Can I use the terms coupling constant and strength of interactions, interchangeably, or are there more subtleties to the term coupling constant that I am not aware of? Coupling Constants from ...
4
votes
0answers
926 views

What is a Fermi arc?

What is meant with a Fermi arc in the context of Weyl semimetals? Is this the just a one-dimensional Fermi surface? For example, in electron-doped graphene, the Fermi surface consists of 2 disjoint ...
3
votes
0answers
213 views

What is a “fiduciary” quantum state?

In Giovanetti et al.'s paper "Quantum Random Access Memory" (arXiv:0708.1879) they state: If the qutrit is initially in the $|wait\rangle$ state, the unitary swaps the state of the qubit in the two ...
3
votes
0answers
123 views

Terminology for a thermodynamic process in which no work is done

Is there an accepted term to be used when the work done in a process is zero? Fermi, in his book on thermodynamics seems to use "isochoric" even when the work is different from pressure-volume work, ...
3
votes
0answers
895 views

What is a Witten diagram?

Recently I heard the terminology of Witten diagram. Studying QFT, I frequently see Feynman diagrams and use them to compute scattering amplitudes, one-loop corrections and so on. In string theory ...
3
votes
0answers
99 views

What is $\mathrm{U(1)}$ vector and axial?

In hadron physics we talked about $\mathrm{U(1)_V}$ (vector) and $\mathrm{U(1)_A}$ (axial) as well as $\mathrm{SU(3)_L}$ (left) and $\mathrm{SU(3)_R}$ (right). There are certain relations between them ...
3
votes
0answers
149 views

How can we count 17 particles in the standard model

This may be a bit of numerology, but I'd like to be able to make a statement like "There are 17 particles in the standard model" with some logical definition of a particle. But this statement is ...
3
votes
0answers
154 views

If the field concept was invented by Faraday, then how did Newton interpret the $g$?

This is Newton's law of universal gravitation. $F=G\frac{m_1.m_2}{r^2}$ Gravitational field $g$ is derived from this formula $g=G\frac{m_1}{r^2}$ This is named gravitational "field" strength. If ...
3
votes
0answers
92 views

What does unfolding of attractor mean?

What does unfolding of attractor mean? Effect of time scales on the unfolding of neural attractors paper talks about Takens embedding theorum. It says that the embedding dimension should be large ...
3
votes
0answers
141 views

What does the term 'a uniform RVB spin-liquid state' mean?

I encountered this term a uniform RVB spin-liquid state in some articles, for example, see the paragraph under Eq.(29) on page 9 in this paper. What does the word 'uniform ' mean? Simply from the ...
3
votes
0answers
450 views

Why supra-conductivity became super-conductivity?

The original article by the Kamerlingh Onnes team in Leiden does not give a name to the new effect: Kamerlingh Onnes, H. Further experiments with liquid helium. C. On the change of electric ...
3
votes
0answers
156 views

How to name different approaches to relativistic quantum theory

In the introductory chapter of the QFT book by Mark Srednicki the author notes that [p. 26] So now we have two different approaches to relativistic quantum theory [...] Which [one of those two] we ...
3
votes
0answers
63 views

What name would you give to the method of approximating an arbitrary magnet with many smaller dipoles?

Let's say I had an arbitrarily shaped permanent magnet, with total magnetic moment $M_{0}$. Ways to calculate the magnetic field of this magnet include an analytic solution (if one exists), as well ...
2
votes
0answers
64 views

Mean field critical exponents and the Gaussian approximation?

A while a go I asked this question on the difference between mean field theory and the Gaussian approximation. This question is related to that. The mean field critical exponents for the Ising model ...
2
votes
0answers
63 views

Mean Field Theory neglects what flucutations?

This is a topic that has being confusing me for a while. A general phrase that is used in the literature is that: Mean Field theories neglect fluctuations My questions is what is meant by ...
2
votes
0answers
96 views

What are disordered superconductors? What kind of research is done in this area?

I was talking with a friend of mine and he mentioned that his professor does research on disordered superconductivity. I had a rough idea of what superconductivity is, but when I looked up the term "...
2
votes
0answers
102 views

The Ising approximation - what exactly is it?

I am slightly confused about the nature of the Ising model to study ferromagnetism. Consider the Heisenberg Hamiltonian with Zeeman term: \[H=-\frac{1}{2} \sum_{i\ne j}J_{ij} S_i\cdot S_j+g\mu_B {B}\...
2
votes
0answers
412 views

Relation between inertia tensor and moment of inertia about an axis

As far as I understood, we define two quantities: Inertia Tensor - a $3\times3$ matrix, which describes the object "mass" of rotation in relation to a certain point, helping us calculating rotations ...
2
votes
0answers
126 views

Configuration space of a classical gauge theory: Physics vs. Mathematics

Let's have a look on a gauge theory on a trivial fiber bundle, as it is seen by mathematicians: We have a trivial vector bundle $(E, \pi, M; V)$ with group structure. We denote the sections of $E$ by ...
2
votes
0answers
75 views

Correct terminology or way to refer to the 2 “types” of ice sublimation

I'm trying to get the right terminology for various forms of phase change. I am familiar with the phase change / triple point diagram for water, and we have various terms for the transition of a ...
2
votes
0answers
926 views

What is the difference between selection efficiency and acceptance in high energy physics?

Often in papers the product of these two quantities is mentioned, but I'm not sure what exactly they mean separately. My guess would be that one of these is the fraction of the events that you are ...
2
votes
0answers
196 views

What is the general definition of a quench?

I've seen the term "quench" used in many different contexts. It's easy to understand the meaning when the context has a simple physical analogue, such as lowering the temperature of a system to cause ...
2
votes
0answers
36 views

What is the name of the basis that uses objects of definite parity?

Currents to which gauge fields couple in four dimensions can be described as follows: $$ \mathcal{L} = -g A_\mu J^\mu. $$ Sometimes it useful to discuss these couplings in the chiral basis, $J_\text{...
2
votes
0answers
73 views

Terminology - optical (visual) properties of a structure

I am trying to understand few terminological problems that I encounter. Without knowing keywords it is hard to perform search for literature or publications in the area. The area relates to the ...
2
votes
0answers
91 views

QFT: What does “finiteness” mean?

As above: what is the definition of a QFT to be "finite"? That all UV corrections are finite and there are no divergences at all? That there are divergences, but these divergences can be absorbed in ...
2
votes
0answers
146 views

Nomenclature of nuclear excited states

I read in an online portal about $^{112}$Sn nucleus making a transition from $0_{g.s}^{+} \rightarrow 2_{1}^{+}$ state. Also, some higher excited states were named as $0_{2}^{+}$, $3_{1}^{-}$, etc. ...
2
votes
0answers
122 views

Why are Lagrangian subspaces called 'Lagrangian'?

I am wondering what the special role of Lagrangian subspaces (or submanifolds) are in mechanics. Do these subspaces have some sort of special property for which we have some sort of `Lagrangian ...
2
votes
0answers
192 views

Morphisms between chiral CFTs

This is a question about terminology. Given two vertex algebras $V_1$ and $V_2$ (= chiral CFTs), there are two kinds of maps $V_1\to V_2$ that one might want to consider. 1) Morphisms of VOAs that ...
2
votes
0answers
78 views

What is the 1/2 spin analog of the graviton called?

In some supergravities you have the gravition, gravitino, graviphoton and graviscalar. Each is analogous to each other in only sharing gravitational properties and nothing else. They differ by spin ...
2
votes
0answers
1k views

de Sitter and anti de Sitter metric

Is the following correct for the distance $d$ from the origin $(0,0)$ to point $(t,x)$ in the 2-dimensional de-Sitter and anti de-Sitter spaces? Here, $t$ is time and the distance may be called the ...
1
vote
0answers
64 views

Difference between Critical and orbital velocity

What is the difference between orbital and critical velocity of satallite ? I have read that critical velocity is constant value and it does not depend upon altitude. It only gives the velocity of ...
1
vote
0answers
47 views

Is there a difference between false (metastable) and local equilibria?

Or is it permissible to use the terms interchangeably? If there is a difference, what is it?
1
vote
0answers
91 views

What is meant by finite harmonic oscillator?

What does it mean to take finite harmonic oscillator, In research article "http://iopscience.iop.org/article/10.1088/1367-2630/17/11/113015 ", we were finding effective number of cobosons in ...
1
vote
0answers
29 views

Is there a term for the study of asteroids?

I'm trying to find the name for the academic specialty of studying asteroids, but I can't seem to find any. For example, there is a distinct wikipedia page for "Planet" vs "Planetary science". Is ...
1
vote
0answers
49 views

Quasi Static Reversibility Theorem

As far as I know, the definition of a reversible process is simply "a process that can be reversed". Meaning, that for an isolated global system containing the subsystem in question, its thermodynamic ...
1
vote
0answers
52 views

Is there a name for symmetry in which fermions and bosons are in identical adjoint representations?

In a Yang-Mills theory, with gauge group $G$, if the Fermions are in an adjoint representation then for every Fermion with "charge" $Q$ there is a boson with charge $Q$. i.e. there is no difference ...
1
vote
0answers
66 views

Stress tensor decomposition and names for different components

The stress tensor can be decomposed into a spherical component (which is a scalar multiple of the identity tensor) and a deviatoric component which is the original tensor with the spherical component ...
1
vote
0answers
61 views

What is meant by “Almost orthogonal”?

Figuratively speaking, when two quantum objects’ states are ‘almost orthogonal’, are they in some physical sense ‘almost blind’ to one another?
1
vote
0answers
16 views

What's the name for the physical attribute that would describe the flexibility of a chain mail?

The individual links of a chain mail are pretty rigid. When deforming a piece of chain mail following its intended use, its flexibility doesn't rely on the elastic or plastic properties of the ...
1
vote
0answers
225 views

What's the difference between a Green's function and a fundamental solution?

The Wikipedia article on fundamental solution says In mathematics, a fundamental solution for a linear partial differential operator L is a formulation in the language of distribution theory of the ...
1
vote
0answers
111 views

Liouville one-form local Vs global meaning

Let's take the so-called Liouville one-form $\theta = \sum_i p_i dq^i$ (AKA Canonical one-form, Tautological one-form, Symplectic potential, etc.), defined on cotangent bundles. Some contributions (e....
1
vote
0answers
77 views

What does it mean when something is called “fundamental”?

Most of the books on science tell that quantum theory and general relativity are the fundamental theories in science. This has always sparked a question in my mind. What does it mean to be "...
1
vote
0answers
201 views

Explicitly proving that the Hamiltonian is Lorentz covariant

I want to show explicitly that the Hamiltonian $$ H = -\Omega V + \int d\tilde{\textbf{k}} \omega (a^\dagger(\textbf{k}) a(\textbf{k}) + b(\textbf{k}) b^\dagger(\textbf{k}) ) $$ is Lorentz covariant....
1
vote
0answers
25 views

What is stabilization of nanopartocles?

What is usually understood under the word "stabilization"? I know that nanoparticles can easily participate in the chemical reactions and unite one with another. And, for example, porous structures ...
1
vote
0answers
165 views

What are collinear mass, visible mass, effective mass, and invariant mass?

What are collinear mass, visible mass, effective mass, and invariant mass? These terms appear quite frequently in particle physics papers but I did not find any resource where these terms are properly ...
1
vote
0answers
27 views

Terminology surrounding superconductors and the Meissner-Ochsenfeld effect

As stated in (Annett, 2004;pg 55) not all materials whose resistances vanishes exhibit the Meissner-Ochsenfeld effect (MOE). Which of these is therefore the defining property of a superconductor (if ...