The h Bar

user218912

22:01

ah I remember

user218912

Feb 10 at 23:54, by 3507

I bought this random qft book from a booksale and idk if I should read it.

Slereah

you can use it as tinder to start a fire

user218912

why shouldn't I read it?

user218912

it seems o.k.

Slereah

oh you can also read it

I never said otherwise

user218912

22:03

it doesn't cover LSZ

Slereah

a pretty big omission

0celo7

weinberg doesn't cover LSZ either.

nor does Zee

Slereah

Peskin does

ACuriousMind

@0celo7 That's not true.

NeuroFuzzy

YES! My copy of Hartshorne just arrived!!!

I can stop being lost in class!

ACuriousMind

22:10

Yay, now you can be lost in Hartshorne!

0celo7

@ACuriousMind Proof?

ACuriousMind

@0celo7 page 438

0celo7

That's literally the reason I think it's a terrible book

NeuroFuzzy

@ACuriousMind For about the next six or seven weeks all I have to worry about is 1.1, 1.2, 2.1, and 2.2! Should be fun!

0celo7

where

@ACuriousMind where is the LSZ formula

Slereah

22:13

he just told you

0celo7

it's not on this page

ACuriousMind

@0celo7 It's "encoded" in the text as "the usual Feynman rules".

0celo7

@ACuriousMind huh?

@ACuriousMind This really frustrated me when reading the book

I do not see it on this page

ACuriousMind

You see the "The above result" in the second paragraph, yes? The result talked about is essentially the LSZ formula, but he didn't write it down again because he already knows how to compute the n-point function by Feynman rules, so saying that the procedure gives "the usual Feynman rules" is enough

I don't see what is surprising about this, Weinberg does everything differently :P

@NeuroFuzzy What, one and a half months to learn the definitions of varieties/schemes?

Or am I misunderstanding what you mean by 1.1, 2.1, etc.

Slereah

Thermodynamics question

I am cold

What to do

ACuriousMind

22:19

Burn stuff

Slereah

What if it's an endothermic burn

I could end up even colder

0celo7

@ACuriousMind No I don't see that...

user218912

it's cold here too.

user218912

like 10 degrees.

user218912

@Slereah dafuq is that?

Slereah

22:21

a joke

user218912

oh

ACuriousMind

@0celo7 Argh, you have a hardcover, don't you? :P

Just go and look in the index for LSZ

0celo7

@ACuriousMind nope

NeuroFuzzy

@ACuriousMind Chapter 1 section 1, chapter 1 section 2, chapter 2 section 1, chapter 2 section 2, over the next 5 weeks. Very doable pace!

user218912

nice I found a worked out solution to one of the problems in my problem set on the internet which I will use to check my work only.

0celo7

22:28

@ACuriousMind does your page look like this?

ACuriousMind

Yes, and I can see "the above result" in the second paragraph clearly in your picture :P

0celo7

Huh?

It literally say "the above famous theorem"

ACuriousMind

Oh, it's theorem, not result, sorry

...was that really the issue?

0celo7

WHICH famous result, dude

that's my problem

NeuroFuzzy

The above one :>

0celo7

22:30

there's a mess of shit on the previous page

and what's with that factor $N$ he mentions

god my QFT is rusty

Slereah

Get the Jabba the Hutt and Gromm book

since u like math so much

0celo7

@Slereah do you even own any math books

ACuriousMind

@0celo7 Aha, so the problem is not that Weinberg doesn't cover LSZ, it's that you find his presentation confusing!

Slereah

@0celo7 I own Robinson

Also Abramowitz Stegun

ACuriousMind

I'll not argue for Weinberg being a paragon of clarity, but this isn't the same as "Weinberg doesn't cover LSZ".

Slereah

22:32

And the integral one

0celo7

@ACuriousMind Ok

"Weinberg does not cover LSZ in any form understandable by nonexperts"

$\cong$ Weinberg does not cover LSZ

ACuriousMind

I dont think Weinberg is intended to be read by non-experts

Slereah

What non-expert is gonna read Weinberg

0celo7

me in high school

ACuriousMind

Neither is any other QFt book, which is why learning it from books is so hard :P

Slereah

22:33

That's like telling some pleb who wants to learn about GR to read HE

0celo7

@ACuriousMind can you please just explain

this is your chance to save me

user218912

@Slereah sounds familiar...

0celo7

BASIC ALGEBRA AND CALCULUS

user218912

someone told me exactly that.

Slereah

It was probably a joke

ACuriousMind

22:34

@0celo7 explain what?

user218912

@Slereah no they were 100% serious.

0celo7

@ACuriousMind page 437

@bloo you got trolled, son

@Slereah Steenrod

Schouten

user218912

@0celo7 :(

ACuriousMind

I can't just pick a random page in Weinberg and start explaining it, I would need to backtrack and decipher the horrible notation first

0celo7

@ACuriousMind Fine.

Next summer, you, me, Weinberg.

We'll read it together

ACuriousMind

22:35

Why would I read a QFT book?

;P

Slereah

I also own a bunch of logic books

But they're not really books

0celo7

@ACuriousMind to help me

Slereah

They're like

Compilation of articles

0celo7

I don't want to hate physics

But Weinberg is why I do

Slereah

Best GR book for plebs, btw

I read that as a kid

It was pretty cool

user218912

22:36

@0celo7 can I join assuming I do well in both my qft courses by that time?

0celo7

no

user218912

wow

Slereah

imo Schwartz to learn QFT

ACuriousMind

@Slereah And there your obsession with weird spacetimes began? :D

Slereah

@ACuriousMind It does speak of wormholes

0celo7

22:37

@bloo you'll be reading Lee

Slereah

Tho my weird spacetime obsession actually stems from Stephen Baxter's books

user218912

@0celo7 why?

Slereah

Since that's where I learned for the first time about closed timelike curves

It's a very poorly documented topic in most basic GR books

0celo7

Slereah

Carroll barely mentions it

0celo7

22:39

@bloo from top to bottom

user218912

@0celo7 what...

user218912

I don't like mathematician books.

Slereah

Here is my tip to learn physics

user218912

lol...

user218912

I agree, once I git gud the learning physics part becomes trivial.

0celo7

22:43

@bloo at least read the bottom one

user218912

@0celo7 maybe someday

Slereah

Wald as an intro might be a bit much

0celo7

well then

I have the perfect book

user218912

I'm reading carroll right now.

user218912

I like it so I won't change books.

0celo7

22:44

Slereah

That pleb book contains an explanation of hawking radiation for children, btw

It involves virtual particle pairs

What a bunch of scrubs

user218912

@Slereah well I'm a pleb right now.

0celo7

@ACuriousMind It's weird, Weinberg's GR book is very lucid

But somehow he's a confused old man in QTF

Slereah

Which is weird because that's what he got the nobel for

0celo7

right

Slereah

22:46

amazon.com/…

Best intro book for GR math imo

0celo7

is it?

why not Lee GSM

got some actual math

user218912

actual math is boring.

Slereah

Actual math does not make for a very good intro

user218912

only the physics part of math is interesting.

0celo7

@ACuriousMind has this chat always been so hostile

I'm putting Weinberg cosmology on my desk cuz it's so good

ACuriousMind

22:48

@0celo7 I don't see any hostility.

Except from you directed at Weinberg, that is :P

0celo7

my desk is being overrun by books :o

Slereah

Callahan is pretty good because it starts with accelerated frames in SR and then embedded curved surfaces

Not a lot of actual GR but it prepares the way nicely

0celo7

23:26

@ACuriousMind help are you still there?

I have a delta potential

$V(x)=-\alpha\delta(x)$

Slereah

I'll give you Steenrod for that delta potential

Mail it to me

0celo7

They want me to compute the discontinuity of the derivative of an eigenfunction

in terms of $\alpha,m$ and $u(0)$, but won't it depend on $E$ too?

0celo7

23:42

^disregard

@bloo learning anything good in Carroll?

Slereah

Carroll has exactly one closed timelike curve

pretty weak imo

0celo7

yikes

Slereah

It's not even a standard example

It's some weird fake spacetime thing

0celo7

oh well that's good?

what's a fake spacetime

implying Godel isn't fake

Slereah

Godel is at least based on a physical model

Rotating dust

user218912

23:59

@0celo7 not yet, working on QFT right now.

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