The h Bar

« first day (4251 days earlier) ← previous day next day → last day (669 days later) »

More Anonymous

3:22 AM

@antimony So basically you want a theory that is 2nd quantized and has no 1st quantized counter part

More Anonymous

3:34 AM

no idea but I'm sure they exist

@JohnRennie I'm still confused about a turning point would play out in special relativity though :///

antimony

3:54 AM

those terms are a bit over my head @MoreAnonymous but definitely sent me on some interesting reading

basically i've concluded there's too many unfamiliar terms for me to properly grasp it, given my current level of understanding

thanks for the breakdown though, its definitely given me some hints on where to look

More Anonymous

@antimony It took me a long time to get a basic understanding of QFT. Its one of those subjects which is super deep and doesnt even have a community consensus (amongst experts) what a good qft book should look like :/

@antimony your welcome

antimony

ahh, yes unfortunately it will probably be a good 6 months before i'm ready to tackle it actually haha

at least

erm *begin to tackle

John Rennie

4:41 AM

@MoreAnonymous It's a surprisingly subtle problem :-)

I've been thinking about it on and off without finding a really simple way to explain it, which is weird given it's such a simple problem.

More Anonymous

@JohnRennie Haha ... lol. I find it disturbing in some sense

I thought of one way. Potential energy (in some sense) is really a energy that can be converted to kinetic energy

John Rennie

The way I've been thinking about it is that the particle does work on the confining potential, and the turning point is when the work done by the particle is equal to its KE.

The KE is frame dependent, but so is the work - the force doesn't change because it's just mdU/dx, but the distance the force moves is frame dependent.

I suspect the two frame dependencies cancel out.

More Anonymous

@JohnRennie Isnt the work done 0?

John Rennie

If you take an infinite potential barrier the work done is undefined because dU/dx is singular at the barrier.

More Anonymous

@JohnRennie Ah okay

John Rennie

4:48 AM

You need to take some barrier that has a continuous potential, and it shouldn't matter what the exact form of the potential is.

But right now I'm not in the best state for physics problems having been to a party last night :-)

More Anonymous

@JohnRennie nice!

John Rennie

It was nice last night, but it's not so good this morning :-)

Manas Dogra

While defining S matrix for a QFT, we need to define multiparticle states...
Discrete "packets" of definite momenta which don't interact when pulled towards infinity.
For example in conformal field theory such interpretations are not possible because it's a gapless theory and there's a lack of scale.

I was wondering whether there are non conformal QFTs which don't admit such multiparticle states in some other way

See [This](https://physics.stackexchange.com/questions/44993/what-is-the-physical-interpretation-of-the-s-matrix-in-qft)

"On the contrary, some quantum field theories...All conformal field theories belong to this class."
All CFT do, but are there non CFTs which also do, that's my question...

Why is hyperlinking not working :(

Rajorshi Koyal

"Reddy defends the high credit growth during his tenure,claiming it was not a bubble. An increase in household financial savings and a reduction in the government's revenue deficit created the situation for genuine growth."
How would the household financial income and reduction in government's revenue impact the prorcess?

John Rennie

5:37 AM

@ManasDogra The formatting features don't work in multi-line posts.

Manas Dogra

5:48 AM

@JohnRennie Any tips for hyperlinking in multi-line posts?

John Rennie

There isn't a solution. You need to split your post into a single line post for the link and multiline post(s) for the rest.

It's one of the mildly annoying things about the formatting in the chat rooms, though as such things go it's low on the scale of pains in the bum :-)

Rajorshi Koyal

@JohnRennie I guess you replied to me.

It has a lot of finance jargons so it needs proper explanation.