Creation Definition and 323 Threads

Homework Statement Given that U upon acting on the creation operator gives a creation operator for the transformed momentum $$U(\Lambda) a_p^\dagger U(\Lambda)^\dagger = a_{\boldsymbol{\Lambda} \mathbf{p}}^\dagger $$ and ##\Lambda ## is a pure boost, that is ## U(\Lambda) = e^{i...

If i had uploaded an image in a website (and if i don't have the image right now in my PC), is there a way to find the date of creation of the uploaded image?

If matter and anti matter can combine to cancel each other out, can your reverse the process to pull matter and anti matter from nothing? I ask in a theoretical sense, not weather we are currently capable or not. Looking forward to your responses!

What does the law say about writing malicious programs? What if I write one and distribute it but I never actually run it myself? What are the repercussions for writing a script that retrieves all the passwords from users on a message board (not this one), provided that I'm not taking any...

Hi all. I am currently trying to determine the specifications of equipment I need to create a plasma. I am looking to generate a plasma in chamber of Helium at a pressure of about 0.6 Torr. My electrodes are around 17cm apart (giving me a pd of 10 Torr cm). By consulting Paschen curves, I see...

Hi. I was wondering why creation and destruction operators a+ and a- do not conmute. Of course, I can show that they don't conmute by computing the conmutator [a+, a-] = -1. But I want to know the "physical" meaning of this. Isn't destruction/creation a symmetric transformation? We "go up...

Homework Statement Prove that the creation operator a_+ has no eigenvalues, for instance in the \vert n \rangle . Homework Equations Action of a_+ in a harmonic oscillator eigenket \vert n \rangle : a_+\vert n \rangle =\vert n +1\rangle The Attempt at a Solution Calling a the...

How does matter be created from light? When a photon strikes a heavy nucleus, it disintegrates and produces a pair of an electron and a positron. Or Two photons are collided and an electron positron pair is produced. Which is true?

Hello everyone this is my first thread I released that the forum doesn't have a Terry Pratchett thread so I thought that I might as well add one. Is anyone else a fan of Terry Pratchett?

Hello! I'm trying to understand QFT for the moment and have a question regarding the basic. So we have a vectorspace (Hilbertspace) of our states. The operator \phi(x) measures the amplitude at point x, whereas the operator \pi(x) measures the momentum density.. The ladder operator...

from what I understand, the higgs boson is basically a wave in the higgs field. I understand that they have a lot of mass, but are they hard to create? are there higgs bosons flying past us every time electrons moves through wires, or do they require intense energy to be created?

1. Evaluate the following (i.e. get rid of the operators)...

Hello everyone! I would first like to say that I am not exactly unfamiliar with these forums; I'm one of those people who is like a... "long -time thread watcher, first time poster." So yes, this is my first post. :smile: I have used these forums as a sort of reference library, looking up...

Hi guys, I consider fermionic holes and I know the creation and annihilation operators of them. I have shown that \vec{S}= \sum\limits_{k \nu \mu} \frac{1}{2} \bf{c}_{k \mu}^{\dagger} \vec{\sigma}_{\mu \nu} \bf{c}_{k \nu} =...= \sum\limits_{k \nu \mu} \frac{1}{2} \bf{h}_{-k \mu}^{\dagger}...

Hi folks, originally I read Peskin & Schroeder but then I realized it was too concise for me. So I switched to Srednicki and am reading up to Chapter 5. (referring to the textbook online edition on Srednicki's website) Two questions: 1. In the free real scalar field theory, the creation...

The fundamental idea of these operators is that we can use them to add particles to our system to a specific eigenstate. Now my book has examples of these operators of which the harmonic oscillator ladder operators are used. But thinking about it, this example does not make sense for me. The...

For a set of energy eigenstates |n\rangle then we have the energy eigenvalue equation \hat{H}|n\rangle = E_{n}|n\rangle. We also have a commutator equation [\hat{H}, \hat{a^\dagger}] = \hbar\omega\hat{a}^{\dagger} From this we have \hat{a}^{\dagger}\hat{H}|n\rangle =...

Hi, Could anyone tell if there exists an identity a_k^\dagger = a_{-k} because intuitively there should be no difference between creating a particle with momentum k and destroying a particle with momentum -k. If true is it possible to show that from the definition a_k = \frac{1}{√V}∫e^{ikx}...

Hi, I'm not sure if this is the correct section to post this. As far as I know, it is widely accepted that antimatter has "normal" gravity, and that for creating a matter-antimatter pair, you need to input the rest mass of the particle in energy (Einstein's equation). But as potential...

Show that $ \displaystyle \int_{0}^{\infty} \left( \frac{1}{x^{2}} - \frac{1}{x \sinh x} \right) \ dx = \ln 2$. I actually might have seen this one evaluated before but in a way that didn't make much sense to me.

Hi all, For a science project, I'm using mist, created by an ultrasonic humidifier. An ultrasonic humidifier uses a membrane that vibrates at ultrasonic frequency to disperse water into tiny droplets, resulting in a cool mist. Now I was wondering; is there a way to reduce the droplet size...

Hello everyone. First of all, I should like to apologize if the question I'm going to ask looks so ridiculous. As far as I know, energy can't be destroyed or created. It only changes forms. So far so good, but how in the beggining did it occur? How was it created? Where/How did the first energy...

I'd like to know if creation and annihilation operators are involved in a free trajectory of a particle from point A to point B. If it's the case, how so? If there is a detector at A, and another one at B, mathematically speaking, can it be said that the particle is annihilated at A, and...

Can creation operators be used to find a matrix representation in a larger dimension? Is that maybe how I could find the 3D representation for SU(2) ?

(please note this is similar to a homework question I have posted but it is not the same and here I am just trying to understand a concept) In a book I was reading it said \Delta^{+} \longrightarrow n + \pi^{+} is a viable process via the strong force because all that is needed is a down...

Hello! :) My background: MSc in engineering (up to, but not exceeding, multivariable calculus) and the rest is just free time hobby research. I ponder things because it's fun. My musings: I enjoy the idea of sets living within some kind of "universe", so that before a set is used or...

My understanding is that in general, operators -- corresponding to observables -- act on a state (itself a member of an infinite-dimensional Hilbert space), and the eigenvalue is the value in that state (at least, if it's a pure state). To get an expectation value, you take the dot product of...

In one dimensional problems in QM only in case of the potential ##V(x)=\frac{m\omega^2x^2}{2}## creation and annihilation operator is defined. Why? Why we couldn't define same similar operators in cases of other potentials?

A dialectic of width d is inserted into a capacitor made up of two plates, with the plates being a distance D apart. D>d. Afterwards, the capacitor acts like it is two capacitor connected in series. Why? I mean how the heck is the dialectic supposed to get induced charges equivalent to the ones...

Hi, As I understand virtual particle pairs can be created outside of the event horizon of a black hole. I understand that they result from Vacuum Fluctuations. What creates these vacuum fluctuations? ***A side note: I hope I'm not violating any rules of the physics forums by creating two...

Hi, ΔEΔt ≥\frac{h}{4\pi} How does this formula relate to particle creation? I understand that it is relevant to the uncertainty principle, but that is essentially all that I am aware of. Does this formula indicate that when a particle with energy 'E' exists for time 't' it then decays...

What's the least energy required to create a fundamental particle of mass m,what would be ur answer? mc^2 or 2mc^2 For fermions,we always have to create anti fermion too... Is it true for bosons too... Say I want to create any boson... Would I have to create 2 of it?

Do I always have to use pair production for the fundamental particles... If I have to produce a fermion,I have to create an anti fermion at the same time? what about bosons? i mean what about those who doesn't have antiparticle? Or do I have to create 2 of them as they themselves are their own...

Is Tidal Energy a "creation" of energy? I would like to discuss very basic idea about conversion of energy. Every form of energy we utilize (solar energy, wind energy, geothermal, fossil, hydro, etc) can be traced back to the exhaustion of some kind of energy and mass. Say solar energy, it is...

I have bumped into a term a^\dagger \hat{O}_S | \psi \rangle I would really like to operate on the slater determinant \psi directly, but I fear I cannot. Is there any easy manipulation I can perform?

We know that a|n> = √n | √(n-1)> and a' |n> = √(n+1) | n + 1 > so, If we use this to find <n|a'a|n> it would be equal to n <n|a'a|n> = n Am I correct? I'm not really sure about my calculations. I operate with a first so. <n|a'a|n> <n|a' √n | √(n-1)> = n ...

So, I'm studying Second Quantization for fermions and came across this equation. I was just wondering why there is a summation needed? And why do we do it with (i≠p).? Please can someone explain this to me? Reply and help is much appreciated.

Initially what was to become the Universe was a particle of very high energy, or in other words a particle with a very high energy state. Some unknown event caused this particle to decay into a lower energy state during which various forms of matter, energies, and fields were produced. At...

I was thinking about using a power drill to spin up a gyro. Let's say this gyro has two segments, a wide center and narrow ends. And its a perfectly rigid body. When the power drill is placed at the wide part, more torque is applied to the gyro and the gyro's angular acceleration is...

Abstract The proposing Method unlike to using now others comprises in usage for plasma creation and its further ignition the created in-situ halo-layer of high-energetic particles to the puffed gas. For realization of Method the following procedures should be performed consistently and...

How do you list creation date of a file in linux bash? I want to find creation date of some files, not just modification date. Thanks.

Hi all Homework Statement Show: (a^\dagger a)^2=a^\dagger a^\dagger a a +a^\dagger a wheres: a= \lambda x +i \gamma p a^\dagger= \lambda x -i \gamma p Homework Equations - The Attempt at a Solution Well, I haven't got much. I just tried to use the stuff given, put it into my...

Many references of quantum field theory begin with an explanation of the necessity of a field theory as opposed to a single particle theory. Sometimes they use the argument that E=mc^2 implies particle creation. For example, in Peskin "the Einstein relation E=mc^2 allows for the creation of...

Hi Guys, I have an query. I would like to know the best tool for Simulation, Geomtry and Mesh creation. I want to simulate a duct with a turbine in it as a Part of my research project. I am beginner for the simualtion field so please suggest accordingly the appropriate software. Also please...

I would like to normal order the following product of creation-annihilation operators, set up in Maple 16 as follows. The problem is, Maple won't perform "expand" (lowercase e) on the last step below (evaluating sigma3(x) :=[op1+op2]*[op3+op4]*[op5+op6] ); , which makes setting up the entire...

hello everybody. i have a quick question. i am going to make a shape memory alloy model in ansys workbench 12.0 . as workbench does not have the SMA model, i have to make material properties in mechanical APDL and then make an input file. but i don't know how to define properties and make the...

First post, long time lurker. Supposing that mankind were to first choose the Moon as the celestial body for colonisation (no questions at this point, those in favour of Mars pretend for a second it has some sort of life on it!), how would we go about creating a significant atmosphere on the...

Well I personally love the "Pillars of Creation" because they are magnificent. I was scanning one picture and i saw what look very close to a face and i thought i would like to share it. Picture 1: "Pillars of Creation" Picture 2: Face cropped out.

what is "Jean's creation" ? sorry if there's already a thread about this,need some help about this "jean's creation". i have no idea about this guys, i only know is it has something to do with interstellar mediums.when i Google search it i came up with:confused: .so I'm asking for a complete...

Homework Statement *see attachment* Homework Equations The Attempt at a Solution Alright, so we just began messing with functions in our class and I'm kinda struggling to grasp this assignment. I believe it should begin like this: shape = menu('Choose a shape','1...