Correction Definition and 178 Threads

The question My Working:

Where does the ##m## in ##(3.2)## come from? It doesn’t seem to enter anywhere in Feynman rules for the given diagram

We know that we need to go to 5th order in perturbation theory to match 10 decimals of g-2 for electron, theory vs. experiment. But let us not assume QED is pure and independent, but it's a lower energy limit of GSW (not Green-Schwartz-Witten from superstrings) electroweak theory. Has anyone...

Hey to all,... It is now generally believed that information is preserved in black-hole evaporation. This means that the predictions of quantum mechanics are correct whereas Hawking's original argument that relied on general relativity must be corrected. However, views differ as to how...

Relevant Equations: My solution: Could someone please verify my answer?

Given the unperturbed Hamiltonian ##H^0## and a small perturbating potential V. We have solved the original problem and have gotten a set of eigenvectors and eigenvalues of ##H^0##, and, say, two are degenerate: $$ H^0 \ket a = E^0 \ket a$$ $$ H^0 \ket b = E^0 \ket b$$ Let's make them...

I recently got a new correction tape. When I was staring at it today (ya I knew I should be studying for calc2), I noticed that the gear ratio between the two gears was notable and fixed. In particular, the bigger gear that unrolls the tape has more teeth than the smaller gear that rolls up the...

What if the value of X is not integer, such as P(X < 1.2)? a) Will the continuity correction be P(X < 1.2 - 0.5) = P(X < 0.7)? or b) Will the continuity correction be P(X < 1.2 - 0.05) = P(X < 1.15)? or c) Something else? Thanks

Before I start, let me say that I have looked into textbooks and I know this is a standard problem, but I just can't get the result right... My attempt goes as follows: We notice that the amplitude of this diagram is given by $$\begin{align*}K_2(p) &= \frac{i(-i...

For example suppose the uncorrected extinction instrumental magnitude is ##v^A_V = 9.00##, will the corrected extinction instrumental magnitude always be greater than ##9##?

I have been trying write a code in for error correction. I am new to programming and am unable to understand what is not alright. Can anyone please suggest some explanation? from projectq.ops import All, CNOT, H, Measure, Rz, X, Z from projectq import MainEngine from projectq.meta import...

Hi everyone, I'm struggling with the proof for the second order energy correction for perturbation theory when substituting in the first order wavefunction. I have attached an image of my current proof for it below, but I'm not sure whether this is the correct approach for it (the H's in the...

Let´s suppose we are observing the sun and measuring some spectral lines. Does the velocity correction´s formula for the Earth include the rotational velocity components of the Sun as well? or rather are we basically measuring both velocity contributes of Earth and of Sun together (receeding...

I'm reading peskin QFT textbook. In page 196 eq. (6.58) it says $$F_2(q^2=0)=\frac{\alpha}{2\pi}\int ^1_0 dx dy dz \delta (x+y+z-1) \frac{2m^2z(1-z)}{m^2(1-z)^2}\\=\frac{\alpha}{\pi}\int ^1_0 dz\int ^{1-z}_0 dy \frac{z}{1-z}=\frac{\alpha}{2\pi}$$ I confirmed the conversion from the first line...

Struggling on how to do this Q I have tried drawing a sketch of it and had come up with this This is probably not right, as the speed of sound is not given here as well the length of the open pipe tube? Any help would be really great! Thanks

Hi all, The power factor correction unit for one of the buildings that I am working on needs maintenance. The service report recommends replacing the existing 25 kVAr unit with 2 x 12.5 kVAr units as "the demand on your site according to the data supplied shows us that at most there is only...

Laplace pointed out that the variation in pressure happens continuously and quickly. As it happens quickly, there is no time for heat exchange. This makes it adiabatic. But Newton believed it to be isothermal. Why isn't it isothermal but adiabatic? Why is there a change in temperature?

I need to apply, with CAMB code, a correction on ##\sigma_{8}## between linear and non-linear regime to keep it fixed (I make change the values of cosmological parameters at each iteration). I have to compute ##\sigma_{8}## from the ##P_{k}## and found the following relation (I put also the text...

Let's focus on the degenerate case. Since in the subspace of the denegerate eigenvectors, ##H^{'}=\begin{pmatrix} -a & 0 \\ 0 &a \end{pmatrix}## is diagonal, then I treat ##\psi _2## and ##\psi _3## with the undegenerate perturbation theory. And I got ##E_2=E_2^0+\left < 2 \right | H^{'} \left...

I had a test article go through a spin balance service. The mass-radius and angular location of the correction weight, to achieve static and dynamic balance, interferes with another component on the test article (I'm unable to place the correction weight at the specified location). Using vector...

If I have a Lagrangian of the form \mathcal{L}=-\frac{1}{2} (\partial \phi)^2 - \frac{1}{2} m^2 \phi^2 - \frac{\lambda}{3!} \phi^6, in 3 dimensions, what is the one-loop correction to the 4-point function? Am I correct in thinking that the following Feynman diagram is the representation of the...

Dear Everyone, I am trying to figure what is the correct phrase in the bolden phrase. The article, where I am doing my research on, states: Let S be the set of all 2x2 matrices with equal positive integral entries. Let T be the set of all 2x2 matrices with equal integral entries. My professors...

Homework Statement Real atomic nuclei are not point charges, but can be approximated as a spherical distribution with radius ##R##, giving the potential $$ \phi(r) = \begin{cases} \frac{Ze}{R}(\frac{3}{2}-\frac{1}{2}\frac{r^2}{R^2}) &\quad r<R\\ \frac{Ze}{r} &\quad r>R \\...

This article (in the picture) states that the end of a compass needle which points toward North is its south pole since the Earth's "magnet" has a North magnet at the North. But in reality, there is a south magnet pole (not sure about that terminology) near Earth's North Pole, attracting all...

In the classical electromagnetic field theory, the field density of energy is given by: $$u = (\epsilon/2)E^2 + (\mu/2)H^2$$ One of the differences between the classical electromagnetic theory and the real world is that in classical EM all charge and current density, (ρ(r), J(r)), is...

The prefix is a bit irrelevant This is on renormalisation. How do they cancel out? Isn't it adding? So the mass experimental = m + (c2correction) so how do you cancel out the m and correction? I'm new to this area (just finished watching lectures by Richard Feynman, specifically a 4 lecture...

This being WRT resonating pipes. Apparently the acoustical length of the pipe is different to the physical length due to the vibration of the sound particles moving the particles at the opening so that the physical length is no longer the length of resonance. I've found many sources on the...

Homework Statement I'm trying to evaluate the following integral to calculate a first-order correction: $$\int_0^\infty R_{nl}(r)^* \delta \hat {\mathbf H} R_{nl}(r) r^2 dr$$ The problem states that ##b## is small compared to the Bohr radius ##a_o## Homework Equations I've been given...

Homework Statement I have ##H'=ax^3+bx^4##, and wish to find the general perturbed wave-functions. Homework Equations First-order correction to the wave-function is given by, $$\psi_n^{(1)}=\Sigma_{m\neq n}\frac{\langle\psi_m^{(0)}|H'|\psi_n^{(0)}\rangle}{n-m}|\psi_m^{(0)}\rangle.$$ The...

I am trying to find or develop an algorithm that can take a 1024 (lets assume random) bit array (so 128 bytes) and, by adding some redundancy (making the final code more than 1024 bits long), make it capable of decoding the data with up to n random bits flipped. Important point is that it has...

I was studying Biostatistics by Zar, the Yates' correction part and stumbled upon this: My doubts: The conculsions are not taking place exactly at the level of alpha- what does this mean? Do the values of Chi square mentioned in table not correspond to the alpha(probability) indicated? Is...

I can't understand a word of https://en.wikipedia.org/wiki/Yates's_correction_for_continuity']Wikipedia.[/PLAIN] P.S. What I know so far is subtracting 0.5 from O-E if df=1 in Goodness of fit (?) is Yates' correction.

We had a switch fail to close on the A phase of a floating wye connected capacitor bank. The C phase fuse was found to be bad and was replaced, however the B phase fuse then blew. The bad switch was then found and replaced. After that the system operated normally. The contractor said the...

In QED, 'electron self energy' to first order results from an electron emitting and reabsorbing a photon. But surely the emitted photon can be absorbed by any other electron in the universe, not just the emitting electron? Indeed it makes no sense to say the photon is absorbed by the same...

Why we must install capacitor in parallel to inductive load? Why not install it in series?

Homework Statement Not sure if this is the correct place for Electrical Engineering Homework help but here goes A single-phased motor connected across a 240-V source at 50Hz as shown in the figure has a power factor of 1.0, I = 20A, I1 = 25 A. Find the capacitance required to give a unity...

Hi guys, the x-ray data booklet gives a modified Bragg's Law that seems to be a combination of Snell's and Braggs. I'll post a picture of what this looks like. I've tried combining the two equations and coming up with their answer but can't get a solid derivation. Any help or a point toward a...

Homework Statement Calculate the second-order correction to the ground-state energy of the stationary states of the system. The perturbed Hamiltonian is: H' =- (/gamma /hbar m /omega)/2 (a+ - a-) ^2 2 & 3. Relevant equatio and the attempt at a solution This is not right. I follow the same...

Homework Statement Hi everybody! While preparing my next experiment (Kater's pendulum), I was given for homework to derive an equation to correct the buoyancy when calculating ##g##. I am given the result: ##g_c = (\frac{2 \pi}{T(\varphi_0)})^2 l_r (1 + \frac{\varphi_0^2}{8} +...

Homework Statement I have problem with the flow rate (Q) in junction that join 2 loops together , where k = 4 , Why in the second correction , the corrected Q in first and second loop = 21 clcockwise for left loop , and for 21 anticlockiwise for right loop ? Homework EquationsThe Attempt at a...

Hello, I have a light AC fan, that I wish to correct its power factor. According to my measurements, it has around 0.7 LAG power factor. Here are my digital measurements: Vsupply = 204VAC I(load) = 0.237Amps phi = 43 , pf = 0.7 LAG My target power factor (pf) is to be 0.85 , and to...

According to the wiki page: http://en.wikipedia.org/wiki/Matter_wave the generalised form for the de Broglie wave is simply: \lambda = h/p I suppose this not correct, because there is no trasform which can change only one side of the equation. In this case we have two variables: 1. a momentum...

Homework Statement Is there a scientiically approved method for end correction of a closed pipe. Homework EquationsThe Attempt at a Solution The formula used is Delta L = (3d) where d = diameter in cm.

Dear All, I have collected temperature data for a period of about 4 months with a device called ibutton attached to the surface of a concrete wall. My problem is the button is made of Stainless steel 305 and exposed to sunlight. I am interested in obtaining the wall surface temperature and at...

Hi there, I have recently been experimenting with solid metal spheres being let to fall through fluids of different viscosities and have recently been introduced to the 'Ladenburg correction'. This correction multiplies the measured velocity of the sphere to obtain the 'correct' velocity used...

Suppose we have an equation in inertial frame A. \begin{equation}\frac{{}^Ad\bf{H}_C}{dt} = \bf{M}_C\end{equation} Now we want to switch to body fixed frame B. For this need to employ correction factor {}^A\bf\omega^B\times\bf{H}_B. Why do we have this correction factor? How to derive this...

Hello. I have a doubt regarding the following problem: 1. Homework Statement Calculate capacitors' capacity to rephase (cos(φF) = 1) the load ZL Homework Equations The formula to calculate capacity in this case is: CY = P(tan(φi) - tan(φF))/ωVrms2 or CΔ = P(tan(φi) - tan(φF))/3ωVrms2...

Hi all, Has anyone an idea about the loop correction for quartic Higss coupling? In [arXiv:1507.03618v2 [hep-ph]], equ. (13) it's pointed out that the perturbativity constrains on the quartic couplings in the Higgs potential is ## \lambda^2 < 16 \pi^2 ## Which means that loop factor is ##...

Hello there ! I need to derive the formula of first order correction to the energy in the case of discrete level of wave function with descrete spectrum.