The h Bar

gonenc

13:00

@0celo7 I have doubts about the existence of the thing, which supposedely throws the die

0celo7

@gonenc yes

> doubting the existence of God

your 3rd world is showing

@gonenc You're looking for (3.4.28)

gonenc

@0celo7 either that or he plays gamble every goddamn second

@0celo7 there isn't any 3.4.28 in my edition, the last one is 3.4.26

0celo7

@gonenc Stop pirating online editions which leave out pages ;)

gonenc

@0celo7 NSA if you are seeing this: I'm not pirating anything.

@0celo7 how am I suppose to find wald so fast if not for internet sources?

0celo7

@gonenc run to the library

Kyle Kanos

13:06

NSA cares about pirating?

I thought it was the FBI who cared

0celo7

@KyleKanos this

gonenc

@0celo7 I live almost in the woods the closest library that has wald is like 10km away!

0celo7

I can walk down the road to the LoC and get literally every book

all the books

all of them

gonenc

@0celo7 note that I live in a 3rd world country meaning that there isn't any english books around here either

0celo7

you should move to the 1st world

gonenc

13:10

besides I already have carroll from the library

@0celo7 I'll in autumn, that is if you count germany as 1st world

0celo7

Hah!

Germany $\subset$ 1st world! Good one!

gonenc

@0celo7 at least they have health care

0celo7

I have military insurance, don't pay a dime.

gonenc

@0celo7 what about the others who has to pay a lot of shiny dimes?

0celo7

@gonenc ::shrug:: Not all of us can have hard working parents.

gonenc

13:14

@0celo7 I really don't wanna continue this discussion

0celo7

You're the one who started it.

Kyle Kanos

I don't pay a dime for the insurance I don't have

gonenc

@0celo7 I know but still...

@KyleKanos ^^this

Kyle Kanos

Plus, @0celo7, you're <18 so you're still covered by your parents insurance

gonenc

@KyleKanos don't you really have health insurance?

0celo7

13:16

@KyleKanos I am covered until age 27 (or is it 23?).

Kyle Kanos

@gonenc Actually, I think my coverage ends in August. My wife & kids don't actually have any

gonenc

@KyleKanos do you think it is unnecessary to have one?

Kyle Kanos

To some extent yes. Insurance, at least in USA, is really to protect you from the expenses of accidents, major illnesses, etc

But it is also used to reduce costs of going to the doctor for well checkups

gonenc

@KyleKanos Dunno, it is mandatory that I have a health insurance before I set foot in Germany

Kyle Kanos

@gonenc Socialized medicine (Germany) vs not (USA)

Though with our cruddy new Obamacare, it's now a tax liability to have insurance

Sorry, tax liability to not have insurance

gonenc

13:26

For QM I have access to Dirac, Feynman, Shankar and Sakurai which one should I read? My goal is to learn path integral formalism

@KyleKanos so I guess you are not gonna renew your insurance even though it is a tax liability

0celo7

Dirac was written before Feynman invented the path integral.

Kyle Kanos

> Greek (brown) letters $\kappa,\,\lambda,\ldots,$ denote spacetime (4D, usually) coordinate indices. Latin (black) letters $k,\,l,\ldots,$ denote spacetime (4D, usually) tetrad indices. Early-alphabet Greek letters $\alpha,\,\beta,\ldots$ denote spatial (3D, usually) coordinate indices. Early-alphabet Latin letters $a,\,b,\ldots$ denote spatial (3D, usually) tetrad indices. - Andrew Hamilton GR,BH & Cosmology notes

0celo7

Shankar is overall a good book and has two chapters on path integrals.

Kyle Kanos

That is going to be confusing for a bit...

0celo7

@KyleKanos Brown?

Coloring indices is definitely not standard.

Kyle Kanos

13:28

@gonenc Well I get my insurance through my university, so since I graduated I cannot renew it. I'll have to get a job in which insurance is provided

@0celo7 Yes, it actually is brown

0celo7

@KyleKanos And those aren't standard.

Kyle Kanos

I'm used to Greek = 4D, Latin = 3D

0celo7

Spacetime = middle Greek, space = middle Latin.

3D tetrad indices?

He's trying too hard.

gonenc

@0celo7 I don't know why they choose that way, I mean in GR and SR you hardly use only spacial components

Kyle Kanos

The notes were linked in this PSE post

gonenc

13:30

spacetime = latin would be much easier imo

0celo7

@gonenc no

@gonenc Depends what you're doing

Kyle Kanos

@gonenc Not to be picky or anything, but it's spatial.

With a T

I keep seeing spacial and thinking special

gonenc

@0celo7 doch I hate to write and read in greek letters and obviously have much more experience with latin letters, which imo makes it easier to read

@KyleKanos oxford also accepts spacial but whatever, next time I'll say spatial :D

Gaurav

hmm.. Daniel Sank comes online once or twice a week, still manages to write a heavily starred comment which stays for the week at the side of the page

0celo7

@KyleKanos Those later chapters are of interest to me

Kyle Kanos

13:33

@0celo7 On spinors?

I'm interested in the GR half & some of the tetrad formalism

0celo7

@KyleKanos Yeah, and the tetrad stuff looks interesting too

I know a lot of that, but some of it I've never heard of

gonenc

oh or should I read L&L QM?

0celo7

Just finish Carroll

gonenc

@0celo7 well I want to plan ahead...

0celo7

@gonenc Do you know any QM

gonenc

13:35

@0celo7 of course I do

0celo7

Just read the path integral chapters in Shankar and Sakurai

Kyle Kanos

This is amazing:

14

Q: Do the beacon lighters really live on top of the mountains?

Following this image I found online: Do the beacon lighters really live on top of the mountains? It seems really cold on top of some of these mountains and there are no villages or whatsoever.

lord-of-the-rings

0celo7

@KyleKanos Can you please check PSE for dupes o fa question involving accelerated observers in curved spacetime?

I can't find anything

0celo7

14:08

-3

A: What is the most common form of antimatter in the universe?

What is the most common form of antimatter in the universe? The proton. Yes, the proton. See this article about positronium which says "to a first approximation it can be regarded as a sort of light hydrogen atom". Positronium is a short-lived exotic atom, comprised of an electron and a po...

huh?

Kyle Kanos

I curiously found this post:

9

Q: Why does large curvature of spacetime imply high temperature?

I`ve just stumbled about a sentence which says that high curvature of spacetime implies that any matter present is at high temperature. This somehow confuses me, so my probably dumb question(s) are: 1) How is this general (?) relationship between the temperature of matter and curvature of space...

general-relativity thermodynamics cosmology

Note the author of the accepted answer?

0celo7

John Baez. So?

Kyle Kanos

Hmm. I guess when we have a Nobel laureate, other famous scientists go out the window?

2

0celo7

@KyleKanos That was exactly my thought.

Kyle Kanos

@0celo7 Yeah, that's just ridiculous. Well worth the -1 to downvote that horrendous post.

ACuriousMind

14:18

@0celo7 huh?

0celo7

@ACuriousMind What?

ACuriousMind

Can't you see the proton is clearly antimatter? :P

0celo7

I found a typo on page 306 of Wald.

Density does not have units g/cm$^{-3}$

Kyle Kanos

@ACuriousMind No, pls ELI5

0celo7

ELI5?

Kyle Kanos

14:19

@0celo7 ....?

sigh ELI5 = Explain Like I'm 5

0celo7

@KyleKanos Wald forgot to delete the negative in the exponent.

I'm smarter than Wald.

Kyle Kanos

Ah, I see now

ACuriousMind

@KyleKanos The proton is positively charged. The positron is positively charged. The positron is antimatter. Therefore, the proton is antimatter.

0celo7

Lol, "black holes are small and black, and thus extremely difficult to observe"

ACuriousMind

That is the whole argument here, I think

0celo7

14:22

Wait, is an antiproton matter then?

ACuriousMind

Yes, didn't you read the post? :D

0celo7

I'll ask him that

Kyle Kanos

@ACuriousMind Hmm. That seems rather intuitive.

0celo7

So a proton (antimatter) has quark content $uud$...is a baryon with quark content $\bar u\bar u\bar d$ then regular matter? Is an antiproton not antimatter!? Confusing terminology, no wonder I've gotten this whole matter/antimatter thing wrong this whole time, — 0celo7 11 secs ago

Haha, you know Wald loves black holes. "Primordial black holes produce virtually no observable effects unless there are sufficiently many of them to affect cosmological evolution or one of them strikes the Earth."

It's like when the cosmic string people say the best way for us to find one is if one passes through the Earth

0

Q: Can you express the Feynman propagator as a limit?

At first I thought that the Feynman propagator was the limit of: $$ G(x) = \frac{1}{x^2 + i \varepsilon} $$ But if you apply the wave equation to this you get: $$ \Box G(x) = \frac{\varepsilon}{(x^2 + i \varepsilon)^3} $$ So it seems this not the solution to $$\Box G(x) = \delta_4(x) $$ (Wh...

quantum-field-theory integration propagator

@ACuriousMind OP does not understand Greens functions?

yuggib

@0celo7 Let's say that the standard physicist's knowledge of partial differential equations is (in my opinion) not sufficient compared to how much they're used in physics...

ACuriousMind

14:38

@0celo7 no shame in that, given how they're taught.

0celo7

How do you define the Green's function rigorously? That free delta is triggering me

yuggib

@0celo7 As a tempered distribution in $\mathscr{S}'$

0celo7

@yuggib I see...not really

ACuriousMind

Yuggib is better than me to talk to about this, I think ;)

yuggib

$\delta$ is a distribution, and you can define the derivative of distributions

0celo7

14:42

Mmm, rigor overload. I'm doing a GR proof right now...my proof is a pretty picture!

Some lines and dots = good enough for me

yuggib

so the Green function is a distribution satisfying the equation (in this case $\square G=\delta$)

in a distributional sense

0celo7

@yuggib I'm not completely sure what this means

yuggib

@0celo7 and this is why I say that PDEs (and the theory of distributions) are not known sufficiently well among physicists :-D

0celo7

@yuggib I'm not a physicist

I have a high school diploma ;)

yuggib

nevertheless you are studying physics...

;-)

0celo7

14:47

I need the result of the theorem to prove the theorem...not good

It's not even a theorem, it's mentioned casually in the discussion!

yuggib

@0celo7 (and many mathematicians would surely be crying seeing what you call a proof...)

:-D

0celo7

@yuggib I like drawing pictures (spacetime diagrams, penrose diagrams, etc.) for these geometrical proofs

Sometimes I can see which theorems to apply

Sometimes, like in this case, not

yuggib

Of course they are useful...but sadly not a proof
many times, however, a rigorous proof is not known

so something is better than nothing I guess

0celo7

I'm trying to prove the horizon of a black hole is contained within the black hole (regarded as a set)

For that I need to prove the casual past of future null infinity is an open set

yuggib

Future null infinity is an open set?

0celo7

14:59

Not sure...

yuggib

if yes, you have "only" to prove that the dynamics (geodesic flow) is a continuous map

0celo7

Wald's sketched proof uses $M\cap J^-(\mathscr{I})=M\cap I^-(\mathscr{I})$

yuggib

(for the dynamics I mean the map that associates to a point its causal future)

I don't know what those symbols mean...

($M$ and $I^-,J^-,\mathscr{J}$)

0celo7

Manifold, chronological past, causal past, null infinity

yuggib

I believe that any decent definition of the causal map $(I^{-})^{-1}$ should grant it is continuous...but that's just intuition

If it is, and $\mathscr{I}$ is open, as I said the proof is finished.

however I really don't know anything about that stuff

so take my words as probably wrong

0celo7

15:10

I'll keep it in mind

But Wald's proof contains something that seems like it's just wrong...

0celo7

15:23

@FenderLesPaul you non-afk?

FenderLesPaul

@0celo7 I am now

0celo7

@FenderLesPaul You near Wald?

FenderLesPaul

Yep

0celo7

I'm stuck on his proof that $J^-(\mathscr{I}^+)$ is an open set on page 308

In particular, I don't understand why $p$ and $r$ can always be connected by a timelike curve

Once I get that, I think I know how to complete the proof.

FenderLesPaul

Theorem 12.2.1?

0celo7

15:28

No

FenderLesPaul

oh

above that

0celo7

Second paragraph under the heading

Yeah, I definitely know how to complete the proof once I show p and r can be connected that way.

Kyle Kanos

Why the heck does Linux Mint think I'm British!?

It is telling me that center is wrong while centre is right

0celo7

"Kanos" sounds Greek/British

Kyle Kanos

And it always wants me to spell it behaviour instead of behavior.

colour instead of color

The dictionary is set to US English, so this makes zero sense

FenderLesPaul

15:31

what's the definition of an unbroken null geodesic, vs a broken one?

Kyle Kanos

@0celo7 It is neither

0celo7

@FenderLesPaul piecewise I think

FenderLesPaul

ok

0celo7

Like a broken X geodesic is piecewise X

FenderLesPaul

in that case, since $p\in J^{-}(q)$ can't you take the null geodesic that connects $p$ to $q$ (such a curve must exist since $p$ is in the causal past of $q$) and then take the null geodesic that connect $q$ to $r$, in accordance with the null generator of scri+, and then piecewise connect these two null geodesics? This is a causal curve connecting the two. I don't think it has to be timelike; he just says causal.

0celo7

15:36

If p can be connected to r via a null geodesic, by the corollary to 8.1.2 p can be in J but not in I

since I=int J, this is bad if we want to show J is open

note the "which is not an unbroken null goedesic"

We must show that there is a timelike curve connecting p and r so corollary 8.1.2 doesn't kick in

FenderLesPaul

does that hold if it's a piecewise null geodesic?

0celo7

not sure

But if you take the null geodesic along scri, that's not piecewise, is it?

FenderLesPaul

no but isn't the piecewise curve the combination of the null geodesic connecting p to q through $J^{-}(q)$ and then the null geodesic connecting q to r that lives in scri?

0celo7

But that's just a straight shot and corollary 8.1.2 should apply

google tells me Wald never defined "unbroken null geodesic"

Hawking-Ellis seems to define unbroken geodesics as those whose tangent vectors are everywhere continuous

FenderLesPaul

wait

0celo7

15:48

I think maybe the intersection with M has some importance

Is perhaps scri not contained within that intersection?

that would explain everything

FenderLesPaul

oh

yes scri lives in the conformal extension; the "unphysical" space-time

it doesn't live in $M$

0celo7

GDI that was my first though D:

I dismissed it

Alrighty then

FenderLesPaul

cool beans

0celo7

@FenderLesPaul This is best seen like this: $\partial M=\mathscr{I}^+\cup\mathscr{I}^-\cup i^0$, but since $M$ is an open set it does not contain its boundary, right?

FenderLesPaul

indeed, I would agree

0celo7

15:56

damn you Hawking for making GR into point set topology

skill patrol

damn you Moore for making point set topology

0celo7

@Danu A distinct disadvantage of being in a suit is that bathbroom breaks (particularly #2) become arduous.

cnn.com/2015/07/21/opinions/drexler-infidelity-website/…

I would expect something like that in GTA...I can't believe that's real.

Kyle Kanos

16:11

@0celo7 I find it funny that there were ~37 million gullible people who paid for a service like that (the promise of "full delete").

0celo7

@KyleKanos I take it you're not on that site?

Or you just didn't request that service.

Kyle Kanos

No, I wouldn't cheat on my wife because I, unlike those other guys (maybe?), actually like her

FenderLesPaul

heh Ashley Madison

Danu

Lololol 37 million people who sign up to an official cheating website

that's an amazing social experiment

skill patrol

How so is it amazing?

Danu

16:23

Even if I was cheating (or planning on it), there's something inside me that would never want to make that "official"

skill patrol

Would you call that a moral conscience?

Danu

No, more like "avoiding responsibility"

skill patrol

aren't they just networking...

Kyle Kanos

@Danu Wouldn't that be more like reducing the possibility of getting caught

Danu

@KyleKanos Those two are pretty similar

Kyle Kanos

16:28

And still, the easiest way to not get caught doing something is to just not do it :D

skill patrol

That^ is an ethnical conscience

Danu

Cheers to that :D

skill patrol

:-)

Danu

Alas, I've already "seen some shit" in my social surroundings and know that this attitude is not feasible for everybody :P

skill patrol

Cheating?

Some have the attitude that it's only cheating if you get caught, right?

Danu

16:33

lol

Hypocrisy is what truly defines humanity

2

0celo7

From topology to the ethics of cheating. Only in the PSE chat

skill patrol

You started it :P

0celo7

Good point, I started both discussions :D

I wonder if the math chat has wholesome discussions like we do

Danu

Nope

skill patrol

Not really

Danu

16:38

I tried to have some fun there sometimes, but they don't seem to get into it

skill patrol

Too sensitive

Danu

I think the chat is just much more serious---people there are not really trying to have fun

skill patrol

Things get flagged, mods come in, people get suspended....

Danu

You can tell @skillpatrol had some issues there.. ;)

ACuriousMind

@Danu I'm not trying to have fun here, either - it just happens :D

Danu

16:41

They're explicitly trying not to ;)

skill patrol

True that^

ACuriousMind

Btw, I just barely passed algebraic geometry...f**king ample sheaves...

0celo7

@ACuriousMind ouch

ACuriousMind

Good thing the grade doesn't count :D

skill patrol

You can just take some courses to get a pass, right?

ACuriousMind

16:50

@skillpatrol for the physics MSc here, only a few grades count, most are just pass or fail

skill patrol

17:18

No wonder physics MSc's don't get along with math MSc's; because when they meet in each other's classes one just wants a pass while the other needs an A. @ACuriousMind

0celo7

17:28

So that's why MSE chat is so serious

ACM can screw off and play PoE 25 hours a day while his math counterpart needs to study algebraic geometry 25 hours a day :P

skill patrol

More importantly when they meet in the MSE chatroom sparks fly.

58 mins ago, by skill patrol

Things get flagged, mods come in, people get suspended....

obe

@0celo7 Aerodynamics isn't cool?

Kyle Kanos

@0celo7 still leaves 3 hours for work/fun though:

4

David Z

17:43

@Danu mathematicians are still trying to prove the existence of fun from first principles

4

ACuriousMind

Field with one element

In mathematics, the field with one element is a suggestive name for an object that should behave similarly to a finite field with a single element, if such a field could exist. This object is denoted F1, or, in a French–English pun, Fun. The name "field with one element" and the notation F1 are only suggestive, as there is no field with one element in classical abstract algebra. Instead, F1 refers to the idea that there should be a way to replace sets and operations, the traditional building blocks for abstract algebra, with other, more flexible objects. While there is still no field with a single...

This is math's idea of "fun" :D

Or, more precisely, $F_\text{un}$.

skill patrol

:D

ACuriousMind

@KyleKanos That...describes my schedule disturbingly well

David Z

Wow... so they've actually proven the nonexistence of fun

0celo7

I've never heard ACM mention food actually.

ACuriousMind

17:47

Apr 19 at 1:30, by ACuriousMind

My main undergraduate research consisted in finding out how many consecutive days I can eat frozen pizza :P

Kyle Kanos

@ACuriousMind I tried that first year of undergrad. Didn't mesh so well with work & school

0celo7

Huh

I stand corrected

ACuriousMind

@DavidZ Yeah...for them, it's something that somehow should exist, but doesn't :P

2

0celo7

@skillpatrol so what happened with you and MSE chat, anyway

ACuriousMind

@KyleKanos It's not actually my schedule, I sleep seven times a week...I think

David Z

17:49

(our chat sidebar is crazy :-P)

ACuriousMind

I like it

skill patrol

Me too

ACuriousMind

@0celo7 Yeah...I'm not a model student :P

0celo7

How will you get a postdoc under Urs if you don't even know the mathematics of grain crops!!?

skill patrol

in Mathematics, 7 mins ago, by Huy

@TedShifrin: The physics department of our uni has dedicated blackboard-assistants. They sit in the lectures and whenever the professor runs out of space, they either move the blackboard up/down correspondingly or clean it for him. Unfortunately, the maths-department isn't quite as wealthy.

ACuriousMind

17:58

@0celo7 1. I have as of yet no idea when and where I want to do my postdoc. 2. I can do well with sheaves...there was just more stuff in the exam than I expected about a specific subset of them that I didn't think very important

obe

@skillpatrol Normally it's the opposite.

At UofT the physics department cannot even afford their physics outreach anymore. In fact canada is the only country in the world that doesn't pay for their physics students to compete in the physics olympiad. lol.

skill patrol

Orly?

ACuriousMind

@skillpatrol Same here, although there are only assistants for the large experimentalist lectures (who then also prepare and maintain the experiments that are shown). The theoreticians are left to fend for themselves.

skill patrol

I see.

Anyway, that was just a small sample of the kind of discussions that go on there concerning the two subjects.

You guys are welcome to come and lurk anytime :-)

If you want to see trolling taken to a whole new level @0celo7 come to the EL&U chatroom.

ACuriousMind

@skillpatrol: Do you spend your life on the SE chat network? ;)

obe

18:14

@ACuriousMind entire life*

skill patrol

Nice correction^

Way too much of it @ACuriousMind :-)

0celo7

@obe it's boring

@ACuriousMind 1. yeah right 2. yeah right

Kyle Kanos

Probably important:

51

Q: Is this really how p-values work? Can a million research papers per year be based on pure randomness?

I'm very new to statistics, and I'm just learning to understand the basics, including p-values. But there is a huge question mark in my mind right now, and I kind of hope my understanding is wrong. Here's my thought process: Aren't all researches around the world somewhat like the monkeys in the...

hypothesis-testing statistical-significance p-value

Danu

@ACuriousMind Whaaaaat? :P

ACuriousMind

@Danu Yup. :)

0

Q: What's heaviest, a pound of hay, a pound of gold, or a pound of lead?

It does seem like the hay would be the heaviest as it looks big. However they are all in the unit pounds, so...shouldn't they weigh the same?

mass weight

Really? Self-answered question? About that?

@KyleKanos That's one HNQ that deserves to be one!

Danu

18:24

Lucky you

Kyle Kanos

Isn't that a bad joke?

ACuriousMind

@KyleKanos p-values, the weight thing, or my grades? :D

Kyle Kanos

@ACuriousMind Yes :D

I mean that weight one

Danu

@ACuriousMind Seriously that should be closed guys

Kyle Kanos

Dupe of this:

5

Q: Is a block of cotton heavier than a block of iron?

if i have a block of cotton and a block of iron each containing a weight of 100 kg when measured on a weighing machine, in reality which one is heaver than the other, which one is heavier and why? This question was in my physics worksheet. The teacher gave the following answer: the apparent weig...

mass weight

ACuriousMind

18:26

@Danu I posted it here to get inspiration for a good reason

...or to have KyleKanos' magic abilities find the dupe :D

Kyle Kanos

It's not an exact dupe though

But answers do discuss the difference between measuring forces & masses

ACuriousMind

...these things are all just boring semantics, to me

@KyleKanos dupey enough for me :P

skill patrol

Don't you mean "syntactic nonsense" ;)

Kyle Kanos

Since 3 of yous agreed with Danu, I voted to close as dupe just to provide context for it since they're sorta related

ACuriousMind

@skillpatrol Nah, it's people quarrelling about the precise meaning of "weight of a block of X" - that's semantics, if I'm not mistaken (I could be).

0celo7

18:32

vtc as "not physics" is correct IMO

skill patrol

Of course you're not mistaken @ACuriousMind I'm just trolling you pal :-)

0celo7

@skillpatrol 1st rule of troll club: don't talk about trolling

skill patrol

Who said I'm apart of that club?

Kyle Kanos

The first rule of tautology club is the first rule of tautology club.

ACuriousMind

^WTF

Kyle Kanos

18:36

(waiting for first person to link to the relevant XKCD link......)

0celo7

We shalle see later?

lol wat

ACuriousMind

@0celo7 That's probably the least objectionable thing in there :D

Kyle Kanos

@ACuriousMind That is pretty WTF-ish. I mean WTF is Nach Holder

0celo7

GG ACM

Danu

@ACuriousMind Sei "the dual exponent" lol

ACuriousMind

18:37

And that's from my actual functional analysis script (which is taught in German)

Danu

dat German english

what is this nonsense

Kyle Kanos

Engrish

Danu

too lazy to translate it from wherever he/she copied it I figure lol

"we daher have" lmao

Also is this like an elementary course?

ACuriousMind

@Danu It is the only functional analysis course there is here (PDE is it's sort-of-continuation)

Danu

I wonder how LMU's level of functional analysis compares to other German MSc programs

@ACuriousMind Ah okay

I guess the Bavarians are more into it

0celo7

18:39

@ACuriousMind Cramming for the functional analysis exam?

Danu

we have 3 on FA, 2 on PDE's :P

ACuriousMind

And we didn't do any spectral theory :(

Only Sobolev ~~shit~~ stuff

0celo7

You did all that Sobolev and still have no clue how to do 10.1 in Wald??

obe

@0celo7 ;<

skill patrol

Don't worry Feynman backs you up that it isn't boring @obe

ACuriousMind

18:42

@0celo7 I still don't even know what an "interior cone condition" is and I have no particular desire to learn about it :P

FenderLesPaul

anyone here familiar with the relationship between scaling dimension of operator insertions in a thermal CFT and the resulting temperature perturbation?

ACuriousMind

Also, I'm not really sure what exactly I learned about Sobolev spaces except that I don't care much whether $W^{k,p}$ embeds into $W^{l,q}$.

FenderLesPaul

or have a reference for it?

ACuriousMind

This script is horrible

I think I'll switch to my handwritten notes :P

This also appears at a point in the notes that doesn't have anything to do with the $^*$-topology

"which konvergiert gleichmäßig to ein stetig function"...I really wonder what drugs the guy responsible for these notes was taking.

Danu

Roflmao

This is amazing

yuggib

18:50

@ACuriousMind That type of Sobolev spaces are so not useful (at least for a physicist)... Only $H^{s}(\mathbb{R}^d)$ and $\dot{H}^s(\mathbb{R}^d)$ matter

Danu

Ist it easy?!

ACuriousMind

@yuggib The lecturer asked us at the end for any comments. He just looked at me funny and told me "Hilbert spaces and spectral theory are...not that interesting" when I said I'd have liked more (or at least some) of that :D

yuggib

@ACuriousMind T__T

ACuriousMind

@Danu It continues like this for about two pages :D

It's really weird...it is perfectly fine German, and then it randomly switches to this gibberish.

@yuggib Pretty much the look on my face

user54412

@ACuriousMind Reminds me of the time an applied mathematician I knew was in a diff eq course that started with "What type of equations do you want to solve?" Everyone named an equation and was told "we'll solve that" but my friend said "Schrödinger" and got the response "impossible."

Transcript for