Symbol Definition and 377 Threads

In Alan Turing's On Computable Numbers, he explains in his second paragraph the general notion of computable numbers. In doing so, he writes "In [symbol][symbol] 9, 10 I give some arguments...". I will include a screenshot of these symbols in this post. Do any of you know what these symbols...

Hello, Trying to set up some production checks and encountered a symbol I have never seen before. I googled machine stock symbols and found something along the lines of what I need to know but could not figure out what the 3.0 besides the squiggly line means. I have attached a PDF with the...

I am reading Adhikari and Adhikari's (A&A) book, "Basic Modern Algebra with Applications". I am currently focussed on Section 9.7 Exact Sequences. On page 387, A&A give Theorem 9.7.1. A&A use symbol in the exact sequences that looks like an oh but I think it should be a zero. They continue...

I have come across the dielectric constant represented by two variants of epsilon. Is there any convention behind the two variants such that: \varepsilon is the SI Dielectric Constant \epsilon is the CGS Dielectric Constant or does it really depend on the writer and how frisky they feel?

In T. S. Blyth's book on Module Theory, the author uses a large 'times' symbol (similar to a capital X) for the Cartesian Product as seen in the text below (taken from Blyth page 58) Can someone help me with the Latex code for such a symbol?Peter

I've run across a symbol on a NASA paper from 1984 that I am not familiar with and that I could not find in a web search. It's a capital 'V' with a horizontal cross bar through its center. Any ideas?

I used a ticker to measure to measure the acceleration of falling object. And and now I am writing report about it and the problem is what symbol is used for the marks on the ticker tape? Like for grams (g). What would you use for marks(?) ?

I used a ticker to measure to measure the acceleration of falling object. And and now I am writing report about it and the problem is what symbol is used for the marks on the ticker tape? Like for grams (g). What would you use for marks(?) ?

In many posts with large LaTeX symbols, such as summation sigmas or the parentheses of a matrix, the upper part of those large symbols aren't displayed until you highlight them. If you then scroll them off the visible part of the page and then scroll back, they're messed up again. You should be...

Homework Statement Use the LC symbol to calculate the following: $$\nabla \times \frac{\vec{m} \times \hat{r}}{r^2}$$ Where ##\vec{m}## is just a vector, and ##\hat{r}## is the unit radial vector and ##r## is the length of the radial vector. Homework Equations On the Levi Civita symbol...

Homework Statement This is my first exposure to Einstein notation and I'm not sure if I'm understanding it entirely. Also I added this class after my instructor had already lectured about the topic and largely had to teach myself, so I ask for your patience in advance... The question is...

Hi. Is using the Levi-Civita symbol to calculate cross-product combos like A x (B x C) allot faster than just using the good old determinant method? I ask because my lecturer in electrodynamics 2 told us it is better, but it seems to me that it's going to cost me time to learn to use this...

I'm trying to explicitly show that \varepsilon^{0 i j k} \varepsilon_{0 i j l} = - 2 \delta^k_l I sort of went off the deep end and tried to express everything instead of using snazzy tricks and ended up with \begin{eqnarray*} \delta^{\mu \rho}_{\nu \sigma} & = & \delta^{\mu}_{\nu}...

As part of a physics calculation, I have the following integral $$\int d \bar x a^{\sigma} \left[-\partial_{\mu}\left(\frac{\delta x^{\nu}}{\delta a^{\sigma}}\right) (\partial_{\nu}\Phi )\frac{\partial L}{\partial (\partial_{\mu}\Phi)} + \partial_{\mu}\left(\frac{\delta x^{\mu}}{\delta...

Hello. I am trying to get OpenGL working on my machine using SDL and glew. I've created a class 'Display' that pretty much just sets up the display and provides a place to draw things. I have 11 errors. In the errors it references both constructor and destructor in the Display class. Here is...

I just derived the 3-D Cristoffel symbol of the 2nd kind for spherical coordinates. I don't think I made any careless mistakes, but once again, I just want to verify that I am correct and I can't find any place on line that will give me the components of the symbol so I can check myself. Here...

If the discrete summation is symbolized by ##\sum## and the continuous by ##\int##, so, by analogoy, the discrete product is symbolized by ##\prod## and you already thought what is the symbol for the continuous product?

Ansatz metric of the four dimensional spacetime: ds^2=a^2 g_{ab}dx^a dx^b - du^2 where: a,b=0,1,2 a(u)=warped factor Christoffel symbol of a three dimensional AdS spacetime: \Gamma^{c}_{ab}= \frac{1}{2} g^{cd}(∂_b g_{da} + ∂_a g_{bd} - ∂_d g_{ba}) Now how to find \Gamma^{a}_{b}?

I'm reading an old article published by Kaluza "On the Unity Problem of Physics" where i encounter an expression for the Ricci tensor given by $$R_{\mu \nu} = \Gamma^\rho_{\ \mu \nu, \rho}$$ where he has used the weak field approximation ##g_{\mu \nu} = \eta_{\mu \nu} + h_{\mu \nu}## where...

Homework Statement ¿Why \Gamma^{k}_{i j} = (1/2) g^{k p} (g_{i p ,j}+ g_{j p ,i}- g_{i j , p}) can't be writed like \Gamma^{k}_{i j} = (1/2) g^{k p} (2 g_{i p ,j}+g_{i j , p}) if i can say that the metric is symmetric? Homework Equations That is the relevant equation The Attempt at a...

Symbol help -- Mirrors & units question Calculate to the nearest 0.1000 degree the diffraction angle of the first order image produced by monochromatic light of wavelength 5890.0 A as the light passes through a grating of 5500.0 lines/cm. WHAT DOES THE SYMBOL 'A' MEAN?? My guess was 1^-10...

Title says it all. I'm reading a lot about the transition metal dichalcogenides and I often see something like 2H-MoS_2 What does that 2H- mean? My best guess is that it has something to do with a hexagonal lattice or stacking or something. Anybody know?

I just completed a post in the Topology and Advanced Geometry forum regarding the connected sum of two projective planes. I wanted to use the symbol # for the connected sum as is usual in the topology books I am studying - but just typing in the symbol 'upsets' latex and so my post cannot be...

Hi. I was reading a chapter about Stationary Phase Method and I got stuck with this symbol \Subset. I looked it up on tables os mathematical symbols but could not find its meaning. Can you help me? Thank you.

I was reading the Wikipedia article at http://en.wikipedia.org/wiki/Euler-Lagrange_equation and came across several symbols I am not familiar with. An arrow pointing right with a short vertical bar on the left end. What does this special arrow mean? How is it different from an arrow without the...

I find it sometimes confusing dealing with integrals of multi-valued functions in distinguishing a closed integration path, and an integration path which forms a closed loop over the function. They can of course be quite different. For example: $$\oint f(z)dz.$$ Now, is the integration to...

To encode a symbol in binary form, I need 3 bits ,and I have 6 symbols. So I need 6*3=18 bits to encode "We are" into binary form. As shown in http://www.shannonentropy.netmark.pl/calculate My question: 3 bits to encode one then I have to use 16 bits, _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _. How to...

Hi, below image. My teacher use symbol in K-MAP. But not sure how it uses. Myattempt : i got 0 0 0 0 0 0 1 1 0 0 1 1 0 1 1 0 --> Using his technique. Can somebody help me out ?

Hello MHB, I am reading about a rule which I got no clue what it's name is on english but I think that you Will understand. My question is what do they mean with that D_g and D_f Regards, |\pi\rangle

I have checked it is not Greek, looks like Q , am I right? Thanks in advance

Suppose you want to add 2 spin-1 particles. I understand you can get the j=1 triplet by $$e_{ijk}|j\rangle |k\rangle $$ where i, j, k run from -1, 0 , 1. The idea is that levi-civita symbol is a tensor under SO(3) rotations, so the contraction with the $$|j\rangle |k\rangle$$ tensor gives a...

X downward arrow a (is it limit from left) X upward arrow a (is it limit from right) ?

I've just started working through Rudin's Principles of Mathematical analysis. In my opinion, the choice of symbols doesn't promote "rigour" and encourages us to make needless assumptions. For example, when defining an ordered field, the fourth axiom for addition states: To every x...

Hi, can anyone help me identify the big blue boxes' schematic symbol? The actual physical component sort of looks like a small inductor or oscillator. SuperSID Schematic The purpose of this circuit is to be a preamplifier for VLF signals related to ionospheric disturbances, I believe.

Hello, I consider the permutations \sigma_i, where i\in \{1,\ldots,n\}, of the following kind: \sigma_i is obtained by choosing the i-th element from (1,..,n) and by shifting it to the first position; for instance \sigma_3 = (3,1,2,\ldots,n). The parity of \sigma_i is clearly (-1)^{i-1}. For...

Hi guys, Would you please help me by telling me the meaning of the wedge symbol in the equation attached? I=inertia. ω=angular velocity. Since the inertia is constant, then why do we need to add the second term? I mean why isn't the differentiation of (Iω) simply equal to (Iω')?

I'm reading Georgi Shilov's Linear Algebra and at the bottom of page 10 is has an equation a_{ij}=\lambda b_i+\mu c_i +\ldots +\tau ?_i Where the ? is there is a symbol that I don't know. It looks like a curly lowercase f (like an integral symbol with a short stroke through the top part). It...

Sorry for my English. I write with the help of a translator from google. Please help determine what standards of a graphic symbol electric (number of the standard paragraph, the part number)? In one book in Russia were given 4 image transformer (for drawing in the U.S. and Europe). Аnd did...

I happened across this little thing in a formula and I can't find what it stands for in any book/ website :confused: I think it stands for the ground state of an element, but I want to clarify first :smile: The symbol is E0 Its in this formula, which is derived from the energy of an...

Hi, from Srednickis QFT textbook, we know the following coupling of Lorentz group representations: (2,1)\otimes (2,1) = (1,1)_A \oplus (3,1)_S, which yields \epsilon_{a b} as an invariant symbol. Generalising, we can look at (2,1)\otimes (2,1) \otimes (2,1) \otimes (2,1) = (1,1) \oplus...

Hello everyone, I'm going through Edmond's Angular momentum in quantum mechanics and I found a particular expansion of the 9j symbol in terms of three 6j symbols which I didn't quite understand. The problem lies in equation 6.4.1 which I simply don't understand. On page 100/101...

Hi, everyone. In the picture attached, what is the meaning of 0oo? what should I read to understand the meaning?Thank you!

Can someone please explain to me why \epsilon_{ijk}\frac{\partial}{\partial x_i}\frac{\partial A_k}{\partial x_j} = 0 where A is a constant vector field.

Hello everyone, I read in Edmond's 'Angular momentum in Quantum Mechanics' that the symmetry group of the 9j symbol is isomorphic to the group S_3 \times S_3 \times S_2. Why is this? Can anyone shed some light on this?

Homework Statement B=magnetic flux density . A is the vector potential of magnetic field. How to get the formula B=∇A Homework Equations http://en.wikipedia.org/wiki/Magnetic_moment The Attempt at a Solution B=magnetic flux density . A is the vector potential of magnetic field...

{\frac{∂(xy)}{∂x}=x} Going backwards. If we took, ∫x dy we get xy+f(x) Now, the only way that ∫x dy is a valid operation, is if we know that we came from a partial derivative. Why, when taking a partial...

Homework Statement prove, ∇x(ψv)=ψ(∇xv)-vx(∇ψ) using levi civita symbol and tensor notations Homework Equations εijkεimn=δjnδkm-δknδjm The Attempt at a Solution i tried for nth component εnjk (d/dxj)εklm ψl vm εknjεklm (d/dxj) ψl vm using εijkεimn=δjnδkm-δknδjm...

Hi everyone, I read in 'Angular momentum in Quantum Mechanics' by A.R Edmonds that the symmetry group of the 6j symbol is isomorphic to the symmetry group of a regular tetahedron. Is there an easy way of seeing this? I've tried working out what the symmetry relations of the 6j symbol do...

I was wondering why V is a common symbol for voltage. The symbol is not named after the unit volt, because it is older than the volt unit, which dates from 1874. Before that, voltage was potential. In 1828 Green used the symbol V for the potential function which he introduced in his essay on...