Before posting anything, please review the Physics Forums Global Guidelines.
If you are seeking help with a...

Feb2313 08:38 AM
ZapperZ

1 
30,462 
Hi guys, I'm doing a quantum course at the moment, and there's one thing in Binney's book which I don't really...

Feb2314 12:18 PM
unscientific

5 
242 
In this note (http://sgovindarajan.wdfiles.com/localfiles/serc2009/greenfunction.pdf) the KleinGordon retarded...

Feb2314 11:50 AM
dextercioby

1 
240 
Dear experts,
Could anyone please confirm or disprove my guess that each Lowdin natural orbital
of an isolated...

Feb2314 09:25 AM
timntimn

0 
215 
In page 30 of book "An introduction to quantum field theory" by Peskin and Schroeder in the derivation of KleinGordon...

Feb2214 08:11 PM
chern

2 
288 
I know that a resonator which is the size of cell isnt in superposition unless its cooled to its ground state. My...

Feb2214 05:18 PM
DaleSpam

7 
469 
Hi all!
So rumor has it, that the spin of a particle is preferably aligned opposite to the direction of the...

Feb2214 03:50 PM
Hypersphere

10 
283 
Hi Guys, I have a question about observable's and superposition's that I haven't been able to find a definitive answer...

Feb2214 02:05 PM
DaleSpam

69 
1,681 
I need help :(
How can I draw a Feynman Diagram, starting with a Lagrangian?

Feb2214 12:42 PM
ChrisVer

2 
320 
Hi guys. I'm trying to get the idea of probability density for 1s hydrogen atom.
I just don't understand that...

Feb2214 10:51 AM
jtbell

3 
344 
Hello,
I happened to open up an old book by Sah, and in it he says:
"it is evident that the electron orbit...

Feb2214 10:24 AM
shallowbay

2 
240 
The probabilistic nature of QM seems apparent(in theoretical formulation as well as experimentally), then why do most...

Feb2214 06:29 AM
Vanadium 50

52 
1,395 
In BRST symmetry the action is
Inew=I0\phi]+s\psi\phi,\omega,\varpi,h].
Where ω and \varpi is ghost and anti...

Feb2214 02:59 AM
ndung200790

9 
401 
Spin1 matrix Sx, Sy, Sz are traceless 3*3 matrix, and have the property ## = i\epsilon_{ijk}S_k##, and we know that...

Feb2214 01:04 AM
Chenkb

4 
285 
This could be one of those questions where I'm hindered by my lack of knowledge on the subject, being only a freshman...

Feb2114 07:04 PM
mfb

1 
254 
I am not sure again, whether this belongs here or in mathematics.
When we have a partial differential equation, in...

Feb2114 04:36 PM
Hypersphere

6 
431 
Electrons emit and absorb photons all the time. I heard that each electron is surrounded by a cloud of 10^{20}...

Feb2114 12:59 PM
anorlunda

4 
261 
I know that any unitary operator on the spin1/2 Hilbert space can be identified as a fixedaxis rotation operator up...

Feb2114 11:49 AM
cattlecattle

0 
280 
hi,
ive got a really simple question.
niels bohr proposed a model of the atom in witch the electron cannot fall...

Feb2114 09:11 AM
ZapperZ

14 
401 
it seems that people never talk about the wave function of a few anyons
why?
i guess the reason is that if they...

Feb2114 05:43 AM
atyy

2 
199 
Hi guys, i've been reading a paper recently about trapping pseudo molecules in a magnetic field gradient. It says at...

Feb2014 10:22 AM
f95toli

8 
355 
In looking up "quantum gates", e.g. "Hadamard gate", all I come across is the matrix representations of the...

Feb2014 04:00 AM
Zarqon

8 
307 
i guess in the wigner crystal, the exchange interaction between the electrons can be neglected.
What is your...

Feb2014 02:35 AM
freshman123

1 
233 
A>=a0>+b1>
<AA>=probability amp <AA>^2=probability
If the state is same, so <AA>= a^2+b^2=1....

Feb2014 02:28 AM
freshman123

5 
360 
I was reviewing the infinite square well, using D.J. Griffiths, and came across this small point of confusion. The...

Feb1914 08:38 PM
Ravi Mohan

3 
236 
After reading Times article on DWave today I got to thinking...
The geometry of the Minkowski plane can be...

Feb1814 05:23 PM
JeremyEbert

0 
263 
Hello, I've been trying to define <p2> in terms of <x2>, much the same way that you can write <p> = m d<x>/dt, because...

Feb1814 10:28 AM
Simon Bridge

1 
280 
Hello everyone, I'd like to start off by expressing my appreciation for the existence of this forum to begin with. I...

Feb1814 05:52 AM
bhobba

6 
314 
given two system is entangled, A>=(0_{A}>+1_{A}>)/√2, B>=(0_B{}>+1_B{}>)/√2. entangle state AB>what is the...

Feb1814 03:03 AM
bhobba

2 
291 
The uncertainty in this principle is talking about uncertainty of measurement or particle itself?

Feb1814 01:49 AM
Maui

14 
399 
Quantum mechanics says that physical observables are selfadjoint operators. Is this correspondence a bijection, ie...

Feb1714 08:18 PM
bhobba

12 
818 
Question about quantum spin:
So for the Schrodinger equation, the angular momentum of a wavepacket, whether it is...

Feb1714 07:57 PM
WannabeNewton

3 
381 
hello
How to you rigorously express the orthonormality of a complete set of eigenvectors (q\rangle)_q of the...

Feb1714 07:47 PM
strangerep

21 
1,199 
I am reading Field Quantization by Greiner and Rienhardt and I am trying to prove that
i\hbar \frac{d\hat{b_k}}{dt}...

Feb1714 07:02 PM
Henriamaa

0 
215 
Hi,
I'd like to argue Heisenberg doesn't apply to a collapsed wave...
I always interpretted the Heisenberg...

Feb1714 05:21 PM
atyy

32 
1,144 
What ever happened with QFT? Heard so much about it years ago now only once in a while will a past Nobel laureate...

Feb1714 02:27 PM
ZapperZ

22 
1,179 
The electromagnetic spectrum contains wavelengths that are on the scale of macroscopic objects. What I'm not sure...

Feb1714 01:01 PM
phy_infinite

15 
561 
I just listened to a lecture on this, and I'm not sure I quite get the point.
What the lecturer did was examine...

Feb1714 10:08 AM
vanhees71

2 
365 
Consider our universe but with only two particles, say two protons. Inevitably they would orbit mutually about one...

Feb1614 06:12 PM
DaleSpam

9 
457 
Hi PF members. I have got a little worry
I am familiar with the Zeeman term that always appears in the Hamiltonian of...

Feb1514 09:17 AM
Bill_K

5 
429 
I came up with the following idea of a device:
We have a short circuited type2 (to allow more current)...

Feb1514 03:07 AM
goran d

0 
224 