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Feb2313 08:38 AM
ZapperZ

1 
30,462 
In all the introductions to the BornOppenheimer approximation I've seen, they make the following claim:
"If you...

T 09:06 AM
AxiomOfChoice

15 
332 
I am not proposing a particular explanation and just in case you suspect I have something in mind, I must tell you...

T 05:34 AM
craigi

6 
217 
If the probability for a state α prepared initially to be in a state β at a later time is given by:
S_{\beta...

T 03:46 AM
king vitamin

5 
195 
In probability theory a sample space is a set containing all possible outcomes of an experiment and an event is a...

Y 07:56 PM
bhobba

11 
338 
If we suppose we have an entangled pair in position/momentum and, following the argument, we measure position of...

Y 05:59 PM
DevilsAvocado

5 
148 
So I understand the commutation laws etc, but one thing I can't get my head around is the fact that L^2 commutes with...

Y 05:35 PM
Matterwave

29 
475 
We've been assigned Griffiths QM for undergraduate physics. I don't particularly like it, but anyway.
It says that...

Y 05:33 PM
cooev769

6 
196 
Ever since learning about atoms and molecules as a child I have envisioned substances (air, water, metal, etc) as...

Y 05:32 PM
The_Duck

11 
255 
I know I've seen a very short article (35 pages) with a proof of a spectral theorem for rigged Hilbert spaces,...

Y 03:47 PM
dextercioby

4 
161 
Hi,
I wondered if it is theoretically possible that the vacuum energy produces an electron/positron pair which then...

Y 09:37 AM
craigi

3 
147 
Sometimes I see complementarity explained as being not able to measure any wave and particle property at the same...

Y 03:01 AM
DParlevliet

4 
155 
Hi there
I'm reading through Valerio Scarani's "Six Quantum Pieces" and have hit an exercise which requires...

Y 03:00 AM
naima

23 
807 
Hey.
Given that if you measure the energy of a wave function, the wave function must collapse to the eigenstate...

Apr2214 10:13 PM
bhobba

12 
273 
Hi to everyone!
I'm searching information about evidences of photons existence. It seems like the photoelectric...

Apr2214 02:56 PM
JCMaxwell

3 
372 
I read it some where that there is very small decoherence for photons. The reason being that photons do not interact...

Apr2214 01:59 PM
alexepascual

10 
374 
I know how to get Von Neumann entropy from a density matrix. I want to get a real number from measurements that give...

Apr2214 12:46 PM
naima

7 
383 
Recently, I was reading about Hawking Radiation in A Brief History of Time. It says that at no point can all the...

Apr2214 12:36 PM
ChrisVer

6 
225 
Hi!
In the description of the SternGerlach experiment made in Sakurai's book the magnet is shaped to have a...

Apr2214 12:29 PM
UltrafastPED

1 
141 
So what I do know about degeneracy is that it's the size of an eigenspace in a certain state. How would I go about...

Apr2214 03:15 AM
bhobba

7 
274 
Trying to get my head around this one. Given that you can have a proton and an electron in a hydrogen atom for...

Apr2214 01:02 AM
cooev769

7 
213 
Really don't like this book, he's crazy ambiguous, I've looked it up myself on the internet and it makes far more...

Apr2114 10:21 PM
cooev769

3 
160 
Hi,
I was wondering if I could test my understanding on the Smatrix and its role in evolving initial states of...

Apr2114 12:40 PM
"Don't panic!"

6 
282 
Just trying to get my head around undergraduate quantum mechanics and they throw a lot of stuff at you, so some help...

Apr2114 01:46 AM
Matterwave

3 
225 
Photons propagate in a certain direction. When it encounters an atom on its way, and an energy of photon is equal to...

Apr2114 12:23 AM
WannabeNewton

1 
149 
Given that the wave equation can be represented in complex form for simplicity sake, for normalising by multiplying by...

Apr2014 08:49 PM
bhobba

12 
376 
Hey.
Trying to wrap my head around this maths. And given that the wave function is a superposition of a bunch of...

Apr2014 08:47 PM
WannabeNewton

6 
272 
Observing which slit a photon or particle goes through in the two slit experiment results in the formation of a...

Apr2014 07:54 PM
bhobba

21 
1,423 
Am I correct to say that adiabatic switching and wavepackets are two completely different ways to derive the same...

Apr2014 06:27 PM
Einj

10 
288 
Hi,
I want to solve one dimensional Schrodinger equation for a scattering problem. The potential function is 1/ (...

Apr1914 04:07 PM
The_Duck

3 
276 
Hi! According to quantum field theory, must the wave function of two different fermions be antisymmetric?
If I have a...

Apr1914 03:20 AM
Marchigno

0 
176 
I've heard some people say that the wave function and its first derivative must be continuous because the probability...

Apr1814 08:04 PM
bhobba

20 
6,647 
hi! i have a doubt, how can i know the total number of bonding and antibonding electrons given a diatomic molecule's...

Apr1814 11:02 AM
pamelmf

3 
206 
If dark energy is caused by quantum fluctuations, where does this energy come from? Also according to string theory...

Apr1814 01:59 AM
UltrafastPED

1 
240 
Hello, I am looking at the wave equation for the casimir effect and I was hoping if some could tell me what type of...

Apr1814 01:57 AM
UltrafastPED

1 
235 
So my professor said that the Kinetic energy of the particle in a 3D infinite well is dependent on position where in a...

Apr1714 12:18 PM
Bill_K

2 
254 
Hello,
I have been working for a while in weak measurements and I have noticed that some physicists such as Aharonov,...

Apr1614 09:55 PM
Rena Cray

1 
320 
I am aware that the most popular version of the quantum brain theory i.e. the Penrose and Hameroff version has been...

Apr1614 07:27 PM
craigi

15 
679 
Hi all,
I'm sort of struggling to understand the difference between active and passive transformations. I'm...

Apr1614 06:24 PM
Fredrik

4 
264 
Sorry if this is not a very we'll written thread. I have already had to rewrite this three times because of computer...

Apr1614 05:37 PM
MrRobotoToo

5 
425 
Hi , I was working on a group theory problem on CH3Cl( treating it as triangle group ). I could get the 1 electron...

Apr1614 01:07 PM
journeyman1986

0 
195 