# Quantum Physics

- Mathematical description of the motion and interaction of subatomic particles. Quantum Mechanics & Field Theory
 Views: 8,373 Announcement: Two free ways to get Gold Membership! Jan17-12 Meta Thread / Thread Starter Last Post Replies Views Pinned: Quantum Physics Forum Rules Before posting anything, please review the Physics Forums Global Guidelines. If you are seeking help with a... Feb23-13 09:38 AM ZapperZ 1 29,449 Hi, Short question: If you take the inner product of two arbitrary wave functions, and then the gradient of that,... Dec16-13 12:46 AM tom.stoer 7 468 For 2 years now I have been reading posts at my university student forums about how the Copenhagen Interpretation is... Dec15-13 09:54 PM DaleSpam 16 825 I'm going though the particle in a box lesson in my physics textbook right now. I understand all the math, but don't... Dec15-13 03:57 PM WannabeNewton 1 458 Hello, There has been lot many articles, write up(s) pointing out the difference between classical and quantum... Dec15-13 03:51 PM Naty1 18 1,199 The beta function for dimensional reguarlization in MS scheme looks like: β(ε,λ)=-ελ+f(λ) But does this mean... Dec15-13 01:55 PM geoduck 0 241 Hi! In section 3.2 of Ballentine, the author considers the most general effect of a Galilean transformation on... Dec15-13 10:26 AM vanhees71 41 1,618 I have a question about allowed transitions and molecular states. For an electric dipole transition between two states... Dec14-13 02:46 PM tomothy 0 303 Simulations back up theory that Universe is a hologram... Dec14-13 11:08 AM audioloop 5 648 I came across this article today and thought it looked interesting.... Dec13-13 04:46 PM audioloop 12 691 I am learning quantum mechics. The hypothesis is: In the quantum mechanics, all operators representing observables... Dec13-13 12:00 PM George Jones 5 500 Hi In double slit experiment our observe can change the past and in the entanglement our observe affact other... Dec13-13 10:44 AM Quarlep 10 483 Hello everyone, please forgive my lack of knowledge when posing this question. In fact, I know so little about... Dec13-13 10:41 AM jedishrfu 3 390 Lately I have been interested in the many-worlds interpretation, and in particular the way it is described by Wallace... Dec13-13 10:39 AM DaleSpam 60 1,899 Hi, I have a ground state wavefunction, $$\psi_0(\xi) = A_0\exp(-\frac{1}{2}\alpha\xi^2),$$ (##\alpha## is a... Dec13-13 08:45 AM quarkgazer 0 285 This may be a bizarre question, but if the entire universe has a wave function, and wave function collapse for real... Dec13-13 05:30 AM bhobba 31 1,339 When solving for the spherical harmonic equations of the orbital angular momentum this textbook I'm reading.. Does... Dec13-13 01:41 AM Simon Bridge 3 424 What do we mean by the two operators are commutative or non commutative? I wanted to understand the physical... Dec13-13 01:31 AM FarticleFysics 6 666 Hi as an undergrad Physics student learning quantum mechanics for the first time, I'm having a hard time wrapping my... Dec12-13 06:26 PM DeepCut 10 620 Does entanglement work via a wormhole (in space-time)? How does time emerge from entanglement via comparison of an... Dec12-13 11:55 AM San K 17 871 Please demonstrate for me that: In any theory,the propagator \Delta_{f}(k) of a field of type f has asymptotic... Dec12-13 02:45 AM ndung200790 1 294 I was searching the internet for information on Bell tests, when I found an article entitled "Taco Bell tests grilled... Dec11-13 10:59 AM jedishrfu 3 426 Hello, What does it means when a particle having mass "m" in a one dimentional potential well has the potential... Dec11-13 08:59 AM ChrisVer 1 340 I thought it was the coherent state, but since that is an eigenstate of the annihilation operator, and the... Dec10-13 12:01 PM snoopies622 15 548 Since there are quantum fluctuations popping in and out of existence then there should be an friction in the space... Dec10-13 08:24 AM forcefield 10 477 Attached is a derivation of the equation of motion for the fundamental fermionic anihillation opeator but Im having a... Dec9-13 06:36 PM strangerep 8 587 Sorry if it is a silly question: Photons have spin-1 and therefore they have theoretically three possible spin states... Dec9-13 10:41 AM TrickyDicky 3 361 could you jump to Matrix_mechanics#Harmonic_oscillator I do not see why "the matrix element Amn is the (m − n)th... Dec8-13 08:34 PM Simon Bridge 11 631 This is another one of those things that I had always assumed to have a very simple explanation. After all, I've seen... Dec8-13 05:57 PM bhobba 21 1,058 Hi people, I was wondering if anyone knows of any commercial device to measure directly Planck's constant. I mean... Dec8-13 01:23 PM Niceperson27 6 429 I am reading about spin, and I think represents the measured value of spin along the x component. The same... Dec8-13 12:08 PM lonewolf219 5 442 Attached is a line from my book about the spectral function for free electrons. How do they conclude that it is a... Dec8-13 06:05 AM aaaa202 3 423 The Born in ineqality fails experimentally and fails to make sense if we think of quanta as particles. Does it make... Dec8-13 04:19 AM tom.stoer 1 308 Hi there, Is it possible to accelerate one of a pair of photons (while under quantum entanglement) close to the... Dec7-13 07:15 PM audioloop 10 615 I saw an interesting comment in my notes about the E = \pm \sqrt{\vec{p}^2 + m^2} eingenvalues plane wave solution to... Dec7-13 06:10 PM ddd123 0 333 Hello, I understand the classical Lagrangian which follows the Principle of Least Action(A) A=∫L dt But what... Dec7-13 04:10 PM Jilang 14 680 Hi All, When solving the Schroedinger equation for the zero potential situation, what is the argument for... Dec7-13 09:35 AM Shyan 1 350 hi all, i am interested in MRI, and i wish to know what is the scientific theory telling us that the spins will... Dec7-13 08:05 AM Jilang 4 330 Does QED predict that the hypothetical graviton particle will interact with light? I mean it would have to interact in... Dec7-13 02:32 AM tom.stoer 3 502 So my teacher regularly makes mistakes on his powerpoints and this is leaving me feeling uncertain about something he... Dec6-13 03:57 PM Jilang 6 536 I understand that in general, it's not true that in the case of a time dependent hamiltonian, the exponential map of... Dec6-13 12:07 PM Sugdub 6 533