/sci/ - Science & Math

[Anonymous No.10395745]

/mg/ - math gains thread.
Discuss how many theorems you can bench press and laugh at the anon who can't build muscle.

[Anonymous No.10395750]

>>10395745
What math do I need to know to beat touhou?

[Anonymous No.10395759]

>>10395750
>point-set topology
>pointless topology
>homotopy theory
>stable homotopy theory
>retract theory
>dimension theory
>topos theory
>differential topology
>model categories
>homological algebra
>piece-wise linear topology
>every homology theory
>surgery
>deformation theory
At the absolute least.

[Anonymous No.10395777]

>>10395745
rape

[Anonymous No.10395784]

>>10395759
I know the first on the list. How do I into the rest?

[Anonymous No.10395786]

>>10395777
Behold all

The true math samuri of egypt

[Anonymous No.10395810]

>>10395759
>>surgery
Do I look like a premed to you?

[Anonymous No.10395865]

>>10395750
The math about holding shift for focused movement

[Anonymous No.10395910]

>previous thread died without reaching bump limit

[Anonymous No.10395949]

What does it mean for real numbers to be dense? My professor dropped that as part of a proof without explaining it?

[Anonymous No.10395975]

>>10395949
The rationals are dense in the reals in that for any real number you can find a rational number arbitrarily close.

[Anonymous No.10395986]

>>10395975
>The rationals are dense in the reals in that for any real number you can find a rational number arbitrarily close.
Does this mean that for any real and a rational close to it, I can find another rational closer to said real?

[Anonymous No.10395990]

>>10395986
Yes, that's literally what it means.
Proof is essentially proof for sums of powers of two, which works since they form a subset of the rationals.

[Anonymous No.10396031]

>>10395975
So like what class should I have learned that in? Some kind of analysis?

[Anonymous No.10396131]

>>10396031
Either Point set topology or Real anal.
>>10395784
Start with homotopy. Homotopical Topology Fuchs-Fomenko if you're mildly autistic, Modern Classical Homotopy Theory by Strom if you're very autistic.
Read both tbqh.

[Anonymous No.10396142]

Is getting a MA in math at 26 «too late?» I want to complete the non-math BA first before going heavily into math

[Anonymous No.10396172]

>>10396142
No, women I worked with got an MA in math at 45.

[Anonymous No.10396181]

Yukari poster needed: hit me up with some good resources on cohomological Hall algebras. Consider that i'm a brainlet undergrad trying to get ahead. Got through Landau's QFT last summer and it has stuck with me.
inb4 Kontsevich - it takes me ages to read his stuff and in my shithole of a department, mathemagicians are more concerned about jerking over locally very flat modules than babysitting their undergrads through russian papers

[Anonymous No.10396231]

>>10395745

Somebody prove the cusick cheon conjecture so I can get on with my life

[Anonymous No.10396246]

>>10395750
>What math do I need to know to beat touhou?

[Anonymous No.10396362]

>>10395750
Danmaku entropy [math]\rho = \sum_n \sum_{\{x_i\}_i^n}\int\mathcal{D}[X]X[x]\ln X[x][/math], where [math]X[/math] describes the "energy cost" of the trajectories of the danmaku bullets [math]x_i,~ 1\leq i\leq n[/math]. The energy cost here is determined by the elegance of the resulting danmaku pattern.
>>10396181
Not very familiar with cohomological Hall algebras, but taking a swift glace at the nLab article it seems to be focused on constructing structures on which the Feynman push-pull formalism works. For instance, in 2D TQFT we can form correspondences on [math]{\bf Bord}_n^G[/math] (so far only for finite [math]G[/math]) for which the push-pull [math]t_*s^* = Z[/math] gets you the TQFT functor (partition function) [math]Z[/math], and using this we can characterize 2D Yang-Mills with [math]G[/math]-equivariant monopole Heegard-Floer homology theory.
Topological band Hall insulators were the first to be described in this manner, with Karoubi K-theory and the first Brillouin zone playing the roles of the generalized cohomology theory and the 2-Segal space, so I think that's where the name came from. Not sure though, I haven't look into this.

[Anonymous No.10396384]

>Witten is described by some friends and colleagues as racist. His colleague Shigefumi Mori, the Japanese mathematician who won a Fields Medal along with Witten in 1990, describes him as "racist-esque", saying: "Every once in a while there'd be something about Asians and I'd be, 'But Ed, I'm Japanese,' and he was like 'Yes, yes, I don't mean you.' He has a definite Ashkenazi streak, [the belief] that he is physically, spiritually and creatively superior."[25] According to More, in the late 90s, Witten attacked a mixed-race woman with a smashed wineglass, saying "I hate black people".[25]

Wow this photo really has a dark backstory...

[Anonymous No.10396391]

>>10396384
>Yes, yes, I don't mean you
You just know.

[Anonymous No.10396468]

https://www.youtube.com/watch?v=2EDwlglGIrI

[Anonymous No.10396478]

Do you even [math]\LaTeX[/math] bro?

[Anonymous No.10396522]

>>10396478
>Do you even bro?
What did he/she mean by this?

[Anonymous No.10396575]

Why can’t I pass a test in math 1331? Every time I apply myself With tons of studying why do I always fail

[Anonymous No.10396586]

>>10396575
nobody goes to your cracker-jack university we don't know your course codes

[Anonymous No.10396591]

>>10396586
Introductory into mathematical analysis

[Anonymous No.10396599]

>formulate up a cool conjecture
>turns out it was already done years ago
t-thanks

[Anonymous No.10396600]

Can any of you help me in this thread? >>10396511

[Anonymous No.10396605]

>>10396575
How well do you usually do on the HW?

[Anonymous No.10396609]

>>10396605
I haven’t been able to purchase the $150 code for it

[Anonymous No.10396615]

>>10396609
What's your text and have you been doing exercises out of it?

[Anonymous No.10396636]

>>10396615
Twxt is in the code but we’re working on limits and derivatives

[Anonymous No.10396641]

>>10396636
Find Understanding Analysis by Abbott. It has some really intuitive explanations for the proofs behind common calculus tools.

What are you doing to study if you're not doing HW or working out of the text?

[Anonymous No.10396689]

>>10396641
With people who have done the hw and a study session thing

[Anonymous No.10397227]

I like abelian categories.

[Anonymous No.10397407]

>Systems of algebraic equations are trivial to solve using Gröbner bases
>Polynomial equations of degree >4 are unsolvable
How do those two statements commonly made by mathematicians fit together?

Why can't you use the Gröbner base magic to solve this system of quadratic equations:
xz + px + q = 0
x^2 - y = 0
y^2 - z = 0
to find solutions for the quintic equation
x^5 + px + q = 0
?

[Anonymous No.10397420]

post yfw when you realize that every bounded operator on hilbert space is a sum of 4 unitary operators

[Anonymous No.10397429]

>>10397407
>Polynomial equations of degree >4 are unsolvable
They're unsolvable by radicals. This doesn't really mean anything significant (a radical is just something we term roots to certain polynomials).
https://en.wikipedia.org/wiki/Bring_radical#Solution_of_the_general_quintic

[Anonymous No.10397817]

>>10397407
What does a surd as a solution to an equation even mean? People take it for granted, but it's actually (initially) a pretty circular definition. A square root of a number is the number that squares to that number. Hence if I claim that the solution of x^2=2 is the square root of 2, then I'm literally just saying that the solution to that equation is the solution to that equation. It's completely tautological, and doesn't bring anything new.

However, rooted numbers are pretty easy to understand and manipulate, and hence they have become somewhat commonplace. They come from polynomial equations of the form x^n - a = 0, but sometimes they come from slightly more complicated expressions, like x^2 + x + 1 = 0.

A natural question to ask is "what polynomial equations can be solved using only surds?", given that they're such "nice" numbers. An equivalent question is "If I start with the field of rationals Q, and I add elements that are solutions to an equation of the form x^n - a = 0?, what other polynomial equations can I solve?". It turns out that it's always the case for polynomial equations of degree 4 and under, and not always the case for degree 5 and higher, and Galois theory tells you exactly when it can happen.

A natural follow-up question is "what other numbers do I need to add to be able to solve any polynomial equation?". Of course, the preferred objective would be to do this "minimally". If I add all solutions, then of course I can add solve all equations. It turns out that for example, in the degree 5 case, you can completely solve every equation by adding surds and solutions to the equation x^5+x+a=0. The latter terms are not as natural as surds, but they're still pretty simple, and are called Bring radicals.

[Anonymous No.10397899]

Did any of you start late?
I basically quit maths 5 years ago when I was out of middle school, and I forgot a lot of elementary shit, like long multiplication/division. My Plan A (musician) didn't work out, so now I would like to study physics at a university, but my maths skills are WAY behind. Can I just use Khan Academy to learn what I need? I used to be the best in my class at maths back when I tried.

[Anonymous No.10397910]

>>10397899
First tip: proficiency in middle school math is equivalent to not being braindead.

Second tip: it's already been established that you're a failure, so I would drop the pretence that you're not going to fail again.

Third tip: yes, KA is what you're looking for if you're looking to do it the lazy way. There's nothing wrong with being lazy now, but if you pretend to succeed in the upper echelons of undergrad, you're also gonna have to learn how to read books

[Anonymous No.10397917]

>>10397910
I had straight As until I stopped caring for maths at the age of 14, I didn't stop because it was too difficult
And what do you mean KA is "lazy"? Where are the books that teach basic algebra or probability online? On the /sci/ wiki there is only super advanced stuff
I learned Lithuanian by myself last year through the internet, if I can do that I can do anything

[Anonymous No.10397931]

>>10397917
The fact that you stopped at 14 only further implies that you've never actually been challenged in math, you've just been following dumb arithmetic rules and solved stupid geometry problems. This is not what real math is.

KA is lazy because you're not actively engaging with the material, someone else is doing it for you, then has trivial problems at the end. This works with brainlet tier math since anything is so easy, but ultimately this method will collapse under your feet.

You've already outed yourself as bordering braindead by asking where to find books online. These are literally the most common topics in existence. A two word Google search will hand you thousands of resources. If you want a well established book (which is ultimately unnecessary), just search for key words on libgen.

The last sentence almost made me want to slice my veins. No, just because you memorized a couple grammar rules and words doesn't mean you can do anything. Now back to work, brainlet

[Anonymous No.10397934]

>>10397931
ok, tiger mom

[Anonymous No.10397939]

>>10397899
Sure, as long as you actually dedicate yourself.
The other guy has some weird ego shit going on, not sure why he's posting as if his regurgitation of definitions means he knows anything.
As with most things, you get out what you put in. You put in half assed work, you'll get half assed results.

[Anonymous No.10397941]

>>10397910
Rude to be quite honest.
>>10397917
Being proud while asking for help is also rude.
Pick up Lang's Basic maths, it should set you up solidly for uni.

[Anonymous No.10397952]

>>10397899
Try Serre's "A course in arithmetic". Lauded as one of the best books ever written and has a lot of material

[Anonymous No.10397966]

>>10397952
>>10397941
>>10397931
Thanks, I started hating KA because of its slow speed and having to watch tedious videos, I didn't consider reading books (although I should have).
I will try to dedicate all my free time to maths, because I am really desperate right now, and if I don't succeed, everything will crash. I fully understand all the advice I got when I was younger about not neglecting STEM as a musician

[Anonymous No.10397971]

Do you listen to music whilst studying? Or do you isolate yourself from everything to not get distracted?

[Anonymous No.10398085]

>>10397941
>Pick up Lang's Basic maths, it should set you up solidly for uni.
Lang is a meme.

[Anonymous No.10398108]

Algebraic Topology or Algebraic Number Theory? Which to self study?

[Anonymous No.10398113]

>>10398108
what do you like thinking about ?

[Anonymous No.10398123]

>>10398113
I like cryptography actually. I figure algebraic number theory is probably most useful, but all topology interests me and I have heard it has some niche apps to cryptography.

[Anonymous No.10398169]

Anyone know if the irrationals have any interesting dense subsets other than algebraic numbers and all rationals times a random irrational?

[Anonymous No.10398252]

>>10398169
>algebraic numbers
>subset of irrationals

[Anonymous No.10398255]

engineer here
tell me about math

[Anonymous No.10398258]

>>10398252
Obviously the intersection of algebraic numbers with the irrationals.
>>10398255
Praise Poincare.

[Anonymous No.10398262]

What's the best introductory book for topology? I have munkres

[Anonymous No.10398282]

>>10398262
Mendelson. After that, try a proper book like Dugundji.

[Anonymous No.10398339]

Does it take a long time to get autistically good at maths? I am bored of vidya and anime and I need a new hobby

[Anonymous No.10398352]

>>10398339
Math can be fun even if you're not autistically good at it, but yes it can take a lot of time and effort unless you're some kind of savant

[Anonymous No.10398359]

>>10396641
abbott is fucking degenerate, never understood why so many suggest him

jiri lebl is for the real niggas

[Anonymous No.10398519]

>>10398258
>Praise Poincare.
ok I don't actually care about math but I saw posts about touhou
any of you geeks play pcb?

[Anonymous No.10398545]

>>10398108
algebraic topology is not very exciting, but that's just my opinion after taking one course
algebraic number theory is nice, I learned introductory stuff (i.e. basic Galois theory, basic stuff with number fieldsa and Dedekind domains and ideal class groups). Maybe it's autistic but I really like the fact that the theorems still have some connection to concrete computations with numbers, which is rare in other fields

[Anonymous No.10398556]

>>10398108
Algebraic Number theory is cool. I think it can be a bit hard to self-study at times though since some things don't really seem motivated until afterwards.
Here's the lectures for a course I took last semester on it following Stevenhagen: https://www.youtube.com/watch?v=TPCx-b09Vj0&list=PLfN4S4WRkd-yQkSFtsOJAnh410yKtD4z8&index=4

[Anonymous No.10398562]

>>10398556
>I think it can be a bit hard to self-study at times though since some things don't really seem motivated until afterwards.
>falling for the "motivation" meme

[Anonymous No.10398572]

>>10398562
>I just read and memorise abstract definitions without understanding why

[Anonymous No.10398583]

>>10398572
>>I just read and memorise abstract definitions without understanding why
Mathematicians use "we", not "I".

[Anonymous No.10398687]

>>10398583
We just read and memorwese abstract defwenwetwrons wwethout understandweng why.
Mathematicians are dumb.

[Anonymous No.10398695]

Ban appeal finally went through fuck, those were some painful 14 days of phoneposting

[Anonymous No.10398700]

Whose name did you post on last /mg/? I didn't see you outing anyone (unless it was promptly deleted)

[Anonymous No.10398702]

>>10398695
Delete this right now unless you wanna get banned for ban evasion.

[Anonymous No.10398706]

you're right, thanks

[Anonymous No.10398708]

No worries.

[Anonymous No.10398730]

What is the most satisfying thing anyone here has encountered in your studies, be it undergrad, masters, phD, or simply someone just doing math as a hobby?

[Anonymous No.10398771]

>>10398583

[Anonymous No.10398778]

>>10398519
does anyone play touhou and just decide not to play one of the games?
why are you such a moron?
when will you go back to your containment thread?

[Anonymous No.10398781]

>>10398730
gauge theory finally bridged some gap i had in my intuition about physics<->math and suddenly all those representation theory and group theory and other "useless" math courses made perfect sense to me

[Anonymous No.10398795]

>>10398781
you sound like a pathetic little dork
>>10398730
definitely the proof of picard-lindelhof existence uniqueness for ODEs. i was astounded that it was as constructive using something as obvious as picard iteration. just epitomizes how wonderfully nice all ODE are.

[Anonymous No.10398803]

>>10398730
When my rather abstract course on basic algebraic number theory had a rather concrete homework problem: Find all integer solutions to x^2+54=y^3, and after several hours, it all finally clicked.

[Anonymous No.10398819]

>>10398803
algebraic number theory sounds idiotic
you dumbasses are doing a wonderful job of reinforcing my dislike for anything algebraic in this thread

[Anonymous No.10398824]

>>10398562
>taste is a meme

[Anonymous No.10398830]

What's the wackiest topological oddity?

[Anonymous No.10398832]

>>10398830
Hopf fibration, probably.
Or the noncontractible space with contractible suspension.
Or any of Milnor's counterexamples.
>>10398819
How's it going, analysis schizo.

[Anonymous No.10398835]

>>10398824
Taste is the memest of all things 4chan. Thinking your life has gained meaning because you've developed very specific preferences is a pathetic display of self-deception.

[Anonymous No.10398839]

>>10398824
>>taste is a meme
Who are you quoting?

[Anonymous No.10398844]

>>10398730
The algebraic proof of the Ax-Grothendieck theorem (eg. on Tao's blog).
The idea of interpreting a system of statements written in one field inside another field to gain insight on the original problem really struck me.

[Anonymous No.10398872]

>>10398835
>Thinking your life has gained meaning because you've developed very specific preferences
Not my point at all.
>>10398839
Claiming that "motivation is a meme" is ridiculous because it is completely ignorant of the way math is constructed. Definitions are chosen and investigated among the gazillion other possible assemblages of words because they abstract some phenomenon or property of a family of objects of interest (which is a matter of taste).
Mathematical development does not happen in a vacuum: there are fads, trends, etc. So there is always a motivation and subjective reasons why things are the way there are.

[Anonymous No.10398901]

>>10398730
The proof that the axiom of determinancy implies [math]\aleph_1[/math] is a measurable cardinal. It is just such a cute example. It perfectly uses descriptive set theory and computability, to say something about large cardinal properties.

[Anonymous No.10398924]

>>10398730
>What is the most satisfying thing
When I hooked up with an undergrad with a 7" cock and he deformation retracted my ass from [math]\mathbb{R}^2\setminus\{0\}[/math] to [math]S^1[/math].
But in terms of my research it's probably finally understanding Atiyah-Singer.

[Anonymous No.10398930]

>>10398924
In my opinion, you're gay.

[Anonymous No.10398958]

>>10398924
This is the maths thread, please keep such posts at /eng/.

[Anonymous No.10398959]

>>10395745
when do things start to click?

[Anonymous No.10398989]

tfw combinatorialist chad stole my gf

[Anonymous No.10399007]

>>10398989
i thought algebraists were chads.

[Anonymous No.10399019]

>>10398959
Just started clicking for me lad.

[Anonymous No.10399022]

>>10399007
Gigachads:
>Teichmuller theorists (not IUT, classical Teich theory)
>Combinatorialists
Chads:
>Arithmetic geometers
>Complex analysts who aren't Teichmuller theorists
>Algebraists
>Graph theorists
Virgins:
>Category theorists

[Anonymous No.10399048]

>>10399022
why are combinatorialists chads, im currently and undergrad and may have to re-evaluate my future field of choice if this turns out to be true

[Anonymous No.10399053]

>>10399022
What would a logician be categorized as?

[Anonymous No.10399062]

>>10399053
desu logicians are living in a parallel universe, nobody really knows what they are up to

[Anonymous No.10399066]

>>10399007
>>10399022
algebraists are autists playing with legos

[Anonymous No.10399068]

>>10399053
>What would a logician be categorized as?
non-mathematician

[Anonymous No.10399071]

>>10399048
Because most people are either used to working with Algebra's clockwork intuition, topology's formalism or analysis's geometry, so they struggle a lot with combinatorics.
>>10399053
If a group isn't listed it's because it's a mixed bag.

[Anonymous No.10399228]

>graduating in May
>working for one year before sending out grad school applications
>working for another year (!) while I wait for a response
I sure hope this isn't frowned upon.

[Anonymous No.10399263]

>>10398778
you sound angry because your pcb score is low lmao
I bet it's -1/12

[Anonymous No.10399300]

>>10399066
i dont get the analogy

>>10399071
makes sense, the combinatorics professors did always seem incredibly intelligent

[Anonymous No.10399320]

Ok, reading Shafarevich BAG. The tangent space of a curve is defined with some technical condition that makes a lot of sense. However, he then gives an example of the tangent space in the plane at (0,0) to y(y-x^2)=0.

Geometrically this is a parabola y=x^2 and the line y=0 (which coincidentally is the tangent of the parabola). The tangent space is then found to be the whole of the plane. How is it justified for this to be a good definition of the tangent space?

[Anonymous No.10399463]

>>10399320
What is your definition of tangent space?

[Anonymous No.10399602]

How to call a function which generally tends to decrease, but have the occasional spikes? Non-monotonic decreasing?

[Anonymous No.10399644]

>>10398924
>getting fucked by an undergrad
imagine being this desperate

[Anonymous No.10399869]

>>10398924
toymaker here again?
what did i tell you last time rapcak

[Anonymous No.10399911]

>>10399320
Well, if you think as a differential geometer, you know that the tangent space at a point x to a space defined by the vanishing of some submersion F should be the kernel of dF(x).
In the algebraic geometric setting, we set this a priori as a definition. More precisely, if a variety is defined by an ideal I = (f1,...,fp), then the tangent space at x is ker(df1(x)) \cap ... \cap ker(dfp(x)) .
In your case, the curve you are considering is defined by the vanishing of one polynomial with differential zero, hence the tangent space is the whole plane.

[Anonymous No.10399912]

>>10399869
Mek

[Anonymous No.10399917]

>>10399912

[Anonymous No.10400060]

good morning /thg/

[Anonymous No.10400086]

>>10399602
No name. "Usually decreasing" works. Depending on exactly how it increases, "a.e. monotonic decreasing".
>>10399869
>>10399912
>>10399917
Excuse me.
>>10400060
Ohayo.

[miroslav No.10400107]

>>10400086
you are excused

[Anonymous No.10400202]

Tohou is not even a good game. Your autism is shit.

[Anonymous No.10400237]

>>10400202
>not even a good game
ikr?to memorize all the different danmaku patterns and getting 1cc is tough :(
better make memes about my master yukari!

[Anonymous No.10400387]

What are the neccessary and sufficient conditions for existence of inverse CDF?

[Anonymous No.10400415]

>>10400387
your dead family to manifest

[Anonymous No.10400487]

err.. so how many sections has the tangent bundle on P^2?

[Anonymous No.10400489]

8

[Anonymous No.10400502]

Might not be the best place to put this, but does anyone know if there’s any work done towards representing stock market instruments as a quantum mechanical system?

This is more of a math question than a physics question. Can stock market prices be represented through this formalism? Price as a superimposed state of bid/ask prices, price movement dictated by momentum, resistance and support levels akin to energy levels, etc.

Haven’t thought this through very seriously, but at a glance is seems interesting.

[Anonymous No.10400505]

>>10400502
Econophysics is a meme.

[Anonymous No.10400519]

>>10400505
Of course it’s a meme. The foundation of quantum mechanics is a meme. Schrödinger took a complete leap by taking what arose from Hamilton-Jacobi theory to describe QM.

But for the underlying mathematics is still coherent, whether or not it represents physical systems is irrelevant.

[Anonymous No.10400542]

>>10400519
I didn't say that phycis was a meme, I said that physicists dipping from physics, refusing to take a cursory glance at economical theory and randomly throwing physical models at economical data is a meme.
Applying superimposed state shitposting instead of using simple stochastic models is a meme.

[Anonymous No.10400601]

>>10400542
stop fucking talking

[Anonymous No.10400618]

>>10400601
Fuck off.

[Anonymous No.10400620]

>>10400202
>t. angry because he can't 1cc any title, let alone score

[Anonymous No.10400705]

>>10398730
Problem 42 of Algebra by Gelfand

[Anonymous No.10400773]

>>10400107
How did you get into touhou? I thought czechs don't even know about it.

[Anonymous No.10400803]

>>10396362
>Not very familiar with cohomological Hall algebras
>wrote a paper on them few months ago
what did he mean by this?

[Anonymous No.10401016]

>>10400803
try calling his department and ask him

[Anonymous No.10401117]

>>10400803
Part of me thinks he just roleplays all thread, but I just filter most of his stuff anyway so I guess it's not much of a problem regardless.

[Anonymous No.10401222]

>>10401117
he argues on /a/ that sentient minerals are powered by nano-sized fusion reactors
he even has his own server to fuel his ego literally ridiculing anyone and straight off telling them to anhero
you will also find him on /lgbt/ and /r9k/ where he spams his bot for attention
this kind of behavior is so disgusting in our community (well he's a physicist, but still)

[Anonymous No.10401301]

>>10401117
He never mentioned COHA, at least as far as 4chin archives go. The fact that what he sometimes writes actually makes sense without rehashing ncatlab articles and their references just confirms my suspicion that (at least one) touhou autist knows his shit to some degree at least. He also made some sensible posts on BRST that can't be traced to any paper. At the very least, he's proficient in (T)QFT and knows SFT constructions well enough to make intuitively correct statemdnts about those.
But i'm really not sure which touhou autist is the legit one or if he even posts in this thread.

[Anonymous No.10401335]

>>10399228
Grad committees don't care. A significant chunk of people in PhD programs are not straight out of undergrad.
The only thing to be concerned about is making sure your profs still remember who the fuck you are 2 years later to write decent rec letters for you

[Anonymous No.10401352]

>>10401117
I think that's a reasonable assumption. Anything he posts about actual mathematics is riddled with nonsensical statements so I just assume his blogposts about physics are equally bullshit.
Although it's just as possible he's a reasonable physicist who just vastly overestimates how much math he's capable of talking about without sounding like an idiot.

[Anonymous No.10401354]

>>10401301
>actually makes sense
>>/sci/thread/S10356155#p10361083
It's called shitposting.

[Anonymous No.10401420]

i want to learn knot theory

the highest i know is calculus 3

where do i start and what do i read

[Anonymous No.10401423]

>>10401354
What is that supposed to show? It's just very contrived, using weird terminology, but not wrong.
I know he has a habit of answering innocent highschool questions with factoids from latest progress of hep-th, but what he usually writes is factually correct and, in very very very loose sense, answers the question.
Yes, he's shitposting, but his shitposts are pretty funny _and_ mostly correct. He knows his shit, although i've seen some mistakes (might just be the way he twists terminology).

[Anonymous No.10401431]

>>10401423
That's basically what I was trying to say.
>>10401420
Real analysis and topology. IIRC some knowledge of algebraic and geometric topology was also used.
The algebra used in babby algebraic topology is "know the definition of group lmao".

[Anonymous No.10401520]

>>10401420
Here, have some notes to see what's up. LOL.

[Anonymous No.10401585]

>>10401520
Those sure are some ugly floor tiles

[Anonymous No.10401632]

>>10401520
>>>/med/

[Anonymous No.10401648]

>>10395745
middle of calc 2 and bored. what should i learn in the mean time?

[Anonymous No.10401773]

>>10401585
You mean lemmas. I always chuckle when i see this page. Very appropriate.
>>10401632
If you think that's bad, let me dig up your prescription for Khovanov cohomology.

[Anonymous No.10401803]

>>10401632
Here, dilute it with some monodromy when applying. This stuff is too strong.

[Anonymous No.10401825]

>>10401648
Draw me some cute fanart (pic related)

[Anonymous No.10401838]

>>10401803
bad paint

[Anonymous No.10401929]

>>10401773
>>10401803

[Anonymous No.10401958]

why am I getting this wrong?

[Anonymous No.10401989]

>>10401958
well for example look at the horizontal vectors in the one you chose. One starts at (-1,2) so its i(x) component should be -2, but it goes to the right

methinks its the bottom left, the same vector starts at (-1,2) and is to <2,-1>

[Anonymous No.10401996]

>>10401989
no for the first one what I said is wrong, that first vector's i component should be 2

[Anonymous No.10401998]

>>10401989
yeah its not so much the graphing part as it is the magnitude part. what else could they want if not sqrt(x^2+y^2)? nothing else makes sense to me. do they want the I and j in there maybe?

[Anonymous No.10402025]

>>10401929
You have some fetish for him? He's a cool dude, like Motl used to be before the jews got him. He's also at least as talented, if not more. Rapcak's downfall will be much quicker since Canada is even more cucked than the US was in the early 2000's.
Sorry Mirek, i don't think chastity device would suit you, nor that you would resort to such drastic measures.
Also
>matfyz scrubs shitposting on 4channel instead of grinding in their prison cells

[Anonymous No.10402032]

>>10402025
so you like to flatter yourself
nice

[Anonymous No.10402054]

>>10402032
>implying
I wasn't even in the same year. I know him just because my advisor was writing poems about him, figuratively.
Also, touhou autist isn't him, he uses weird terminology even if it was just for the purpose of shitposting.
Also, i can't be him because my english is too bad for someone who'sought to be living in Canada for few years. My political views are flat out illegal in Canada too.

[Anonymous No.10402080]

>>10402054
convinced

[Anonymous No.10402094]

>>10401335
That's what I thought, but a few of my more competitive classmates (i.e. dickheads) told me that it would probably raise eyebrows. Fuck em.
I told my profs that I would visit in one year to ask for letters of rec, but I read online that I should ask for them ASAP instead. Not sure how I'll handle that yet.My cohort has like 6 people and I'll only be gone for a year.

[Anonymous No.10402103]

>>10401958
seriously if anyone has any idea what they would want for ||F|| besides squrt x^2 +y^2 let me know

[Anonymous No.10402107]

>>10402103
nvm just had to reverse the x and y

wow

[Anonymous No.10402116]

>>10402103
>>10402107
this is sad
bunk with me if you ever hit fuck it

[Anonymous No.10402127]

>>10395745
I just wanted to pop in to say that I am jealous of all you guys. I wish I was young again. I wish I paid attention in school. I wish I was a mathematician. My "math level" is at basic arithmetic (I can do long division and multiplication and that's about it).

[Anonymous No.10402136]

>>10402127
LMAO YOU WISH TOYMAKER

[Anonymous No.10402165]

>>10402127
just learn brah

[Anonymous No.10402226]

>>10402127
school is bullshit

[Anonymous No.10402252]

>>10402127
>mocking number theory
the gall

[Anonymous No.10402289]

Help I forgot math. The stuff with the dx/dy stuff. I need to get to the point where I can derive a constant stress cross section for a rod hanging under its own weight. I have forgotten the difference between ODEs and PDEs too although I have to work with them. I think I might be somewhere between calc 1 and diff eq. I just got too good at getting the computer to do math for me that I regressed to the point where I don't understand what I'm doing anymore. Now I don't know if I wver understood it in the first place.

[Anonymous No.10402327]

>>10402289
well fuck I think I really did forget all the way to calc 1. So how can I relearn all this the right way rather than just memorizing the pattern that lets me solve workbook problems? How do I generalize beyond workbook problems?

[Anonymous No.10402337]

Any good reference for the Bousfield-Kan p-completion stuff?

[Anonymous No.10402709]

>>10402337
Bousfield-Kan is surprisingly readable, but provides enough generality to give you Bousfield localization in general.
p-completion is just localization at S/p. (For finite spectra this just p-completes the homotopy groups levelwise.)

If you're looking for something more modern I could say something about how this ultimately comes from a cofiber sequence in Pr^L.

[Anonymous No.10402911]

>>10402289
> I have forgotten the difference between ODEs and PDEs
ODEs involve differentiation with respect to a single variable (often time), PDEs involve differentiation w.r.t. multiple variables (often x, y, z, maybe time as well).

PDEs used in physical models are often restricted to specific forms involving the ∇ (del) operators, specifically gradient, divergence, and curl (and the Laplacian, which is the divergence of the gradient). Physical PDEs are usually invariant under rotation of axes (reality doesn't have defined axes), and the del operators all satisfy this. This all falls under vector calculus.

[Anonymous No.10404008]

Is there a name for a curve similar to a lemniscate, but with two or more crossing points? Like oOo.

[Anonymous No.10404320]

>>10404008
Lissajous?

[Anonymous No.10404321]

who here /better than /physishits/?

[Anonymous No.10404334]

>>10402327
i'd reccomend going back and learning what differentials are and the methods used to define definite integrals (e.g., as a limit of riemann sums) as a starter. beyond that, there are a lot of techniques for integration that will be useful for DEQs. maybe review polar coordinates and stuff like that as well

[Anonymous No.10404387]

>>10401352
He answered a physics question the other day and not even Witten would use those kinds of terms, plus from what I understood it seemed a bunch of nonsense

[Anonymous No.10404401]

>>10404387
>He answered a physics question the other day and not even Witten would use those kinds of terms, plus from what I understood it seemed a bunch of nonsense
I'm not a "he".

[Anonymous No.10404473]

>>10404401

[Anonymous No.10404485]

>>10396384
I didn't know the Nico copypasta spread outside of /mu/

[Anonymous No.10404688]

>>10404008
Owo

[Anonymous No.10404781]

>>10404008
Why not oOoOO? https://www.youtube.com/watch?v=yQwxLGM0sz0

[Anonymous No.10405009]

>>10399644
Hunnie, getting young vigorous cock is a privilege.
>>10398830
>there are fibre bundles that aren't locally trivial
>there are torsion elements in the K-group that aren't represented by Clifford module bundles
>Coleman-Mandula fails in [math]n< 3[/math]
>smooth h-cobordism theorem isn't true in 4D
>4D unitary TQFTs do not in general admit a state-sum construction
These are just things I don't like really.
>>10400502
I heard a talk by a mathematical finance guy who described a stochastic model for optimal stock trading, and the variational method he used is basically just very simple saddle-point approximation of a model in finite-temperature stat mech. In addition the supposedly new "averaging over subpopulation" technique he introduced is just a real-space RG coarse-graining. Taking the analogy further, decade-old stat mech models can be used to describe new novel financial models. We wouldn't even need QM for this.

[Anonymous No.10405030]

>Property 1.1 Two finite sequences of elements in S are identical if and only
if the elements in the two sequences are identical respectively in ordering.

What does this mean?
So basically n^th element in S_1 should equal n^th element in S_2 provided you preserve their orders? Is that it?

[Anonymous No.10405046]

>>10405009
>stays up till 3 am waits for a call
>goes to sleep once a call is coming
nice move cak san

[Anonymous No.10405077]

>>10405030
think about what happens if you take a subsequence of s1 and s2

[Anonymous No.10405081]

>>10405077
disregard.

[Anonymous No.10405090]

Do you guys know where I could read more about this function?http://mathworld.wolfram.com/IrrationalityMeasure.html

[Anonymous No.10405099]

Hardest shit I can do is projectiles on inclined planes. I'd say this is the equivalent of 60kg on Inclined press badumpshhhh

[Anonymous No.10405122]

>>10405090
have you tried any of the 20 sources in the bibliography

[Anonymous No.10405129]

>>10397971
Depends. When I'm doing proofs I like silence. When I'm doing exercises/easy proof I listen to music. Also listening to audio books while doing easier homeworks. But silence is OP

[Anonymous No.10405181]

>>10405129
nailed it

[Anonymous No.10405185]

>>10405009
>fibre bundles that aren't locally trivial
Except that one's obvious.
And decade old stat-mech is already used.
>>10405030
Yes. Ask on /sqt/ next time.

[Anonymous No.10405195]

>>10395745
I can literally feel the harmful intent radiating off this picture. You can see the true PHENOTYPE as it stifles any other weaker auras within range of its tremendous IQ power level.

https://youtu.be/3nJBF_H56Oc

[Anonymous No.10405205]

>>10397420
>ITT: Anon Squares the circle

[Anonymous No.10405243]

>>10402127
It's never too late to learn math and work with it. I've seen 40+ years old boomers going back to school and becoming professional mathematicians of some sort. You might not be able to make huge contributions, but then again, only a select group in this field can. If that's what you love, go for it.

[Anonymous No.10405385]

>>10405243
if you fail at math
remember you can always try physics

[Anonymous No.10405542]

>>10399300
>i dont get the analogy
he's mocking me.

[Anonymous No.10405563]

APPLIED MATH WARNING! This post may contain applied math. What does /mg/ think of this?
discretephysics.org
should we stop teaching engineers PDEs and start teaching them algebraic topology instead?

P.S. there might be big funding for this sort of stuff coming out soon. I can assure you that the amount provided will be rather comfy. The applied problems they want solved might even be easy for you applied algebraic topologists out there.

[Anonymous No.10405573]

>>10405563
>applied algebraic topologists
that's like saying applied motivic homotopy theorists

[Anonymous No.10405574]

>>10405563
Algebraic topology already has applications to physics.

[Anonymous No.10405581]

>>10405573
There are topology professors at my university who do this. It's all data science.

[Anonymous No.10405663]

>>10396599
feel the phenotype building up in your blood

[Anonymous No.10406001]

>>10405574
So does motivic homotopy theory.
>>10405581
>dad i found a cool way to use homology and few other related objects, am i applying algebraic topology yet?
Yes son, my buddy from CS, doing formal verification, is applied algebraic number theorist, applied higher topos theorist and applied higher category theorist.

[Anonymous No.10406004]

>>10406001
Physicist's capacity to apply maths surprises me sometimes.

[Anonymous No.10406022]

>>10406004
I'm more surprised by CS 5-branelets finding applications for all kinds of weird and "unnatural" axiomatic systems. It's almost perverse.

[Anonymous No.10406038]

If I want to be one of those cool physicists who study algebra heavy topics like algebraic topology, should I do a physics MSc or a math MSc?

[Anonymous No.10406053]

>>10406038
>algebra heavy like algebraic topology
Algebraic topology is honestly 40% category theory, 40% topology and 30% algebra.

[Anonymous No.10406057]

>>10406053
>110%
Kill me.
20% algebra.

[Anonymous No.10406133]

>>10406038
>MSc
Try to get into one of the american institutes.
Otherwise the usual suspects - LMU(D), ÉNS(F), MPG(D), MPP(D), UBonn(D), UHannover(D), INFN(I) - Padova and Turin, UU(NL), ETH(CH) + oxbridge. Look for mathematical physics programmes.

[Anonymous No.10406171]

>>10406038
Probably a math MSc, unless you already have an explicit plan what to do in physics (I recommend AQFT)

[Anonymous No.10406514]

Is there a good book for how they came up with all these trucks in differential equations?
We finally went over the complex part of 2nd order linear equations in a long winded fashion, it was great honestly. But that's rare and the book handwaves everything.

[Anonymous No.10406636]

>>10401222
>>10400803
so this guy is some kind of well known entity around here?

[Anonymous No.10406787]

>>10406636
Well, since geometric unity went off clozapine and doesn't come here anymore, he's the second best shitposter on /sci/.

[Anonymous No.10407422]

HELLO HOW DO I SHOW THAT [math] 3(6+7t) \equiv 4 (\text{mod } 8) [/math] SIMPLIFIES TO [math] 5t \equiv 2 (\text{mod } 8)[/math]

[Anonymous No.10407433]

>>10407422
3(6 + 7t) = 18 + 21t = 4 mod 8
21t = 4 - 18 = 16 + 4 - 18 = 2 mod 8
and finally 21t = 16t + 5t = 5t mod 8.

[Anonymous No.10407472]

I have a retarded fucking question. If [math]\Phi_n = 2^{2^n} + 1 [/math] and [math]\gcd(\Phi_n, \Phi_m) = 1[/math] whenever [math] n \neq m[/math], how tf do I show that there exist n consecutive integers [math] N, N+1, \ldots, N+n-1[/math] such that [math]\Phi_1 \big| N, \Phi_2 \big| (N+1), [/math] etc

[Anonymous No.10407484]

>>10407472
chinese remainder theorem

[Anonymous No.10407518]

>>10407484
I know babe but I can't get an answer for the life of me... hol up, lemme give ya the scoop

[Anonymous No.10407533]

>>10407484
How the fuck does the CRT help

[Anonymous No.10407592]

>>10407533
>>10407518
Since [math]\Phi_1, \dots \Phi_n[/math] are pairwise coprime, use CRT to solve the system
[math]N \equiv 0 \mod{\Phi_1}[/math]
[math]N \equiv -1 \mod{\Phi_2}[/math]
...
[math]N \equiv -n+1 \mod{\Phi_n}[/math]

[Anonymous No.10407744]

Can someone help with this problem?

It takes Alice p days to paint a house and Bob q days to paint the same house. If Alice and Bob work in alternating 2-day shifts, it takes them 10 days when Alice starts and 10.5 days when Bob starts. How long does it take to paint the house if both of them work simultaneously?

[Anonymous No.10407780]

>>10407744
>>>/sci/sqt

[Anonymous No.10407794]

How to get started with maths? Like everything that goes beyound +-x/

[Anonymous No.10407795]

>>10407794
Handbook of Mathematics.
https://ambry.pw/item/detail/id/10391?id=10391

[Anonymous No.10407807]

How many hours per a week you study math?

[Anonymous No.10407817]

>>10407592
you can find the solution to this problem in any wikipedia article. It's not difficult just plain straight useless and of no practical use.

[Anonymous No.10407837]

>>10407807
Like four per day? Actual strict studying time, no distractions allowed and without any breaks counted.

This depends on how much else there is to do and on whether there are courses and stuff. But you can easily do four hours, or five.

[Anonymous No.10407853]

Do you know any good books with just collections of problems and solutions?
If not, where do you usually get the problems you work on?

[Anonymous No.10407857]

>>10407807

[Anonymous No.10407890]

>>10407853
Berkeley Problems in Mathematics

[Anonymous No.10407897]

>>10407853
Murty - Problems in Algebraic Number Theory and Problems in Analytic Number Theory

Develops some core concepts of the theory, and then lets you work out everything else via the problems. The second two thirds of the books are just the solutions.

[Anonymous No.10407920]

>>10395745

doing calc for the first time ever this semester, will let /sci/ know how it's going if this thread's still up or there's another

[Anonymous No.10407948]

>>10407890
>>10407897
Thank you, kind anons

[Anonymous No.10408036]

>>10407920
Please, don't bother.

[Anonymous No.10408224]

>>10408036

Oooof now Imma do it for sure

[Anonymous No.10408352]

>>10408224
Oh anon, please share the profound Calc 1 wisdom with us. We beg you.

[Anonymous No.10408375]

I am trying to write a cryptography program but i need help, in terms of group theory, does there exist an algebraic structure that is a set equipped with not a single "operator", but another group? ie a small finite set with an operator that can be used to "transform" the set it is embedded in? what is this called

[Anonymous No.10408409]

>>10408375
A group action? Essentially, the group 'transforms' the entire set, ie each element of the group acts like a sort of function on the entire set. This sounds like exactly what you're looking for.

[Anonymous No.10408498]

>>10407897
Is there anything like that for Probability Theory / Statistics?

[Anonymous No.10408523]

>>10408498
You may like Exercises in Probability from the Cambridge series in statistical and probabilistic mathematics.

[Anonymous No.10409382]

>Log Volume Computations - part 03 - Hull Bound
https://www.youtube.com/watch?v=ls0g09npVt8

>Thm 1.10 - Probabilistic Version - part 01
https://www.youtube.com/watch?v=s4ufdHTMFM8

>Thm 1.10 - Probabilistic Version - part 02 - Minimal Discriminant Term ("First Term")
https://www.youtube.com/watch?v=Q5L-4ZkwypY

>Thm 1.10 - Probabilistic Version - Part 03 - Base Change, Minimal Discriminant, and Q-Pilots
https://www.youtube.com/watch?v=fGY4AdblmUg

[None !QJa7AGw1GY No.10409606]

[Anonymous No.10409617]

>>10409606
Why do you waste your time sith this retarded shit?

[Anonymous No.10409660]

>>10407853
Problems and Theorems in Analysis by Polya and Szego is one of the best books ever written.

[Anonymous No.10409668]

>>10408352

GUNNA DO EET

[Anonymous No.10409670]

>>10398556
how is he relatively good looking and doing algebraic number theory?

[Anonymous No.10409758]

>>10409606
Underwhelming post. Here's an opportunity to fix it:
Why does perturbative theory fail to prove quark gluon confinement in non-Abelian gauge theories in the IR?

[Anonymous No.10409925]

>>10409670
The power of Algebraic Geometry

[Anonymous No.10410621]

Can someone please explain differentiability in R^2 equipped with a Riemannian metric?
I don't see how to obviously extend the definition of differentiability from R^2 with a norm to R^2 with a Riemannian metric. Replacing the norm by the distance to 0 doesn't seem right, you could be working in a subset of R^2 that doesn't contain the origin.

[Anonymous No.10410636]

>>10398687
*Mathematwetweans

[Anonymous No.10410664]

>>10410621
I think you are confused. In R^2. A riemannian metric is the same as the dot product and therfore the same as a norm.

[Anonymous No.10410677]

>>10410664
the metric varies from point to point, you seem confused
>>10410621
differentiability is independent of a riemannian structure, only manifold structure, which I suspect in this case is the same as regular R^2, so you recover your old regular differentiability.

[Anonymous No.10410690]

>>10410677
The tangent space of R^2 is R^2 so the usual metric is just the usual dot product.

[Anonymous No.10410695]

>>10407853
Prasolov: Problems and theorems in Linear algebra
Polya-Szego: Problems and theorems in Analysis
Clark: Elements of abstract algebra
Makarov-Goluzina-Lodkin-Podkorytov: Selected problems in real analysis
Coxeter: Geometry revisited/Projective geometry
Steele: The Cauchy-Schwarz Master Class

[Anonymous No.10410702]

>>10410690
for the usual metric that's true, for a general Riemannian metric it's not

[Anonymous No.10410703]

>>10410621
The existence of a riemannian metric presupposes the existence of a manifold structure, ie. a well-behaved notion of differentiability, since a metric is a "smooth family of inner products".
So, differentiability is the same as usual. It is independent of the metric.

[Anonymous No.10410711]

>>10410702
Changing the Riemannian metric doesn't change the tangent space.

[Anonymous No.10410715]

>>10407853
https://4chan-science.fandom.com/wiki/Mathematics#Problem_books

[Anonymous No.10411138]

>>10410711
it changes the inner product retard

[Anonymous No.10411195]

Anyone else at the MAA golden section meeting?

[Anonymous No.10411200]

>>10411138
The Riemannian metric is the inner product (on the tangent space).
Slight impression that we're having small conflicts in terminology.

[Anonymous No.10411270]

>>10411195
Sheldon Axler is here

[Anonymous No.10411465]

>>10411270
Why should anyone give a shit?

[Anonymous No.10411531]

>>10411465
he has written the most lucid and intellectually complete tractatus on the theory of finite dimensional vector spaces and their homomorphisms, he's a major figure in the pedagogy of mathematics.

[Anonymous No.10411546]

>>10411531
>he has written the most lucid and intellectually complete tractatus on the theory of finite dimensional vector spaces and their homomorphisms, he's a major figure in the pedagogy of mathematics.
he's literally afraid of determinants

[Anonymous No.10411555]

>>10411546
a determinant is often introduced as some odd looking sum of products of permuted elements, not at all clear and not at all intuitive. Intuition can be built up if you introduce them in the context of (hyper)volumes I find, but this can be a little convoluted, and in many cases the theory can be developed without this unnecessary machinery. Axler does a good job of doing this, he also does a good job of avoiding bases and matrices, which is admirable. The matrix is a computational tool for engineers and computer scientists, it should be avoided in mathematics where possible,

[Anonymous No.10411557]

>>10411531
>>10411555
based

[Anonymous No.10411653]

>>10411555
>damn, usually books introduce the determinant without explaining any of the context, so the student doesn't understand any of their properties, and I need to fix that
>but instead of explaining alternating forms like any decent person would, I'll avoid the determinant like the plague

[Anonymous No.10411817]

please tell me there's been other /sci/rants like pic-related

[Anonymous No.10411860]

>>10411653
>posting anime on sci
it must be hard being a non-passing transsexual

discussions of forms are totally superfluous, the book makes no attempt at developing multilinear algebra, tensor algebra, etc., nor does it need to, it effectively accomplishes what a first course in linear algebra needs to accomplish without mention of odd scalar invariants.

[Anonymous No.10412064]

>>10411555
>The matrix is a computational tool for engineers and computer scientists, it should be avoided in mathematics where possible,
shoo shoo frenchie

[Anonymous No.10412621]

>>10411860
>touhou
>anime
don't you belong in the engineering general?

[Anonymous No.10412680]

>>10411860
this must be your first /mg/ thread

[Anonymous No.10412688]

is there a website that is literally like a fucking database of calculus/linear algebra problems i can just grind

[Anonymous No.10412695]

>>10412688
lol

[Anonymous No.10412696]

>>10412695
how is that lol

[Anonymous No.10412803]

Just google "problems in mathematics linear algebra" bro

[Anonymous No.10413046]

>>10411555
>Hypervolume of an n-dimensional parallelepiped is somehow difficult to understand
>"Our students are LITERALLY too dumb to imagine a skewed cube in n dimensions"
I really don't get it. A few things are less intuitive than this, eg. dual space (LinAlg1), and not using the determinant makes properly developing the theory of eigenvectors and so on outright impossible.

[Anonymous No.10413582]

What's something cool in functional analysis I can talk at length on (~20-25 minutes) that is at the undergraduate level?

[Anonymous No.10413590]

>>10413582
Banach algebra maybe. Maybe metric space but that should be a topic of topology. Introductions of infinite vector spaces maybe.

[Anonymous No.10413595]

>>10413590
What are some notable results from Banach algebra?

[Anonymous No.10413599]

>>10413582
Fredholm operators

[Anonymous No.10413613]

>>10413595
Banach algebra as far as I know doesn't really have any notable results. It rather provides the framework with which you get those remarkable results. Then again, I'm a brainlet when it comes to functional analysis. The topic itself is ill-suited for undergrads in my opinion.

[Anonymous No.10413622]

>>10413582
>cool
Atiy-
>undergrad level
Ultraweak and ultrastrong tppologies. The ultra makes it cool.

[Anonymous No.10413627]

I'm 25 years old brainlet, I want to learn math from the ground to the absolute top, in self learning style, wich books and path should I take? Help me mathematicians of sci!

And another question, what branch of math is the most cutting edge in terms of pratical application today?

[Anonymous No.10413645]

>>10413627
calculus and differential equations are the most important mathematics when it comes to practical applications like engineering or sciences.
For physics stuff, you will at least also need differential geometry/topology and complexe analysis. I reckon that books from the 30s to 60s are the best textbooks when it comes to learning it by yourself. The elementary stuff etc. hasn't changed since then anyway.

[Anonymous No.10413664]

>>10413627
>application
Forget about that, you'll eventually lose interest in applicability and gravitate towards pure math when you realize that there's more to math than just use it as a tool.
As for book recommendations:
https://4chan-science.fandom.com/wiki/Mathematics
Follow this wiki.

[Anonymous No.10413681]

>>10413627
>most cutting edge for applications
Probably functional analysis, differential geometry, and a bit of modern number theory for physics.
>PRACTICAL applications
Uh... Complex analysis, numerical analysis, harmonic analysis, PDEs probably? And maybe complexity theory if you even consider that math.

[Anonymous No.10413747]

>>10397899
I did horribly in high school math and I decided to give it another try as a twenty five year old and now I'm in my third year studying physics at a decent university and I'm doing quite well. Anybody can do it. Just figure out if you actually like it before you commit. If you have to force yourself to do it then you will hate it

[Anonymous No.10413823]

>>10413627
>I'm 25 years old brainlet, I want to learn math from the ground to the absolute top, in self learning style, wich books and path should I take? Help me mathematicians of sci!
>And another question, what branch of math is the most cutting edge in terms of pratical application today?

[Anonymous No.10413869]

>>10413582
I mean, quantum mechanics is based on functional analysis and can be taught at the undergrad level. Maybe introduce the machinery with such a motivation?

[Anonymous No.10414135]

>>10413823
this is guide for toymaking

[Anonymous No.10414198]

>>10413869
Wait holup, physicists learn functional analytic quantum mechanics at undergrad? It's not a maymay diluted version without self-adjoint operators and the like?

[Anonymous No.10414253]

>>10395745
I'm a physics major, but who is a jack of all tools at math (quite mediocre). Where do I start? What's the Starting Strength for mathematics anons?

[Anonymous No.10414442]

>>10414198
I doubt that any physicist who isn't into very theoretical work knows functional analysis besides the definition of Hilbert space and basic knowledge of [math]L^2(\mathbb{R})[/math] If you know abstract linear algebra and the spectral theorem of symmetric matrices you have all the mathematical tools to tackle the functional analysis parts of QM texts. That's why almost anyone will tell you it's just linear algebra. Obviously to actually solve shit you need to know the theory and tools to solve linear PDE's, specially separation of variables and fourier analysis. The tools from functional analysis are mostly to develop a general theory using Dirac's formalism, which gives a modern and elegant treatment useful not only for Classical QM, but it's widely used when you want to start entering relativistic quantum mechanics and QFT.

[Anonymous No.10414447]

>>10414253
Depends on your Goals. If you know analysis and some topology, then most subjects become a matter of study and grinding, but remember that you can pretty much be sure that any abstract pure math field has a connection to physics so it will be almost impossible to learn all math relevant to physics.

[Anonymous No.10414453]

>>10414253
I don't know what's the starting strength of math, but as a guy who followed starting strength for muscles and didn't make any progress for years, you don't want to know.

[Anonymous No.10414603]

>>10414453
I used starting strength and people tell me i look great anon. You must've done something wrong anon.
>>10414447
>Depends on your Goals. If you know analysis and some topology, then most subjects become a matter of study and grinding, but remember that you can pretty much be sure that any abstract pure math field has a connection to physics so it will be almost impossible to learn all math relevant to physics.
>>10414447
I don't know either of those. I'm not very strong at proofs, should I start with getting good at proof's?Where do i even begin? Euclid's Geometry lmao?

[Anonymous No.10414629]

>>10414603
>I used starting strength and people tell me i look great anon. You must've done something wrong anon.
No, it doesn't work

[Anonymous No.10414658]

>>10412803
>>10412688
whats the most efficient one though, like i want to just pump out answers and click next, no bs

[Anonymous No.10414752]

>>10414603
Have you taken abstract linear algebra? Start with that, then try any fucking real analysis textbook.

[Anonymous No.10414769]

>>10414658
>find a random number generator
>make it produce matrices
>calculate the determinant, inverses, eigenvectors and eigenvalues

[Anonymous No.10414899]

>>10414752
>abstract linear algebra?
I've taken a linear algebra class, but probably need to brush up. What book you recommend?

[Anonymous No.10415071]

What type of mathematical person would have an easy time with combinatorics? What skills does it implement, it seems to be quite different from much of analysis and a bit more closer to algebra at least from what I can tell (but I haven't taken a course in it so I'm speaking in uninformed generalizations)?
If you've taken the class or have extensive studies in it how do you like it? Is it fulfilling? Also what applications does it have? Thanks in advanced guys

[Anonymous No.10415082]

>>10414899
Friedberg. What I mean is that are you comfortable with the idea of abstract vector spaces? For example, do you understand why the set of all polynomials of degree n forms an n dimensional vector space?

[Anonymous No.10415138]

>>10414769
i want answers and a little bit of how they got the answer right away

[Anonymous No.10415192]

>>10415138
>I want answers
Plug them into R or whatever.
>how they got the answer
By following the algorithm you'll find on any linear algebra book.
>>10415071
Someone who's naturally good with classic number theory and good at breaking problems down into smaller problems.
I honestly don't like it that much. You'll usually approach problems either going completely wild in intuition or by reducing it to some of dozens and dozens of general problems that show up. I suck at the former and the latter sucks.
>applications
Applications of combinatorics are weird. They show up randomly in analysis and algebra.

[Anonymous No.10415255]

>>10415082
the set of polynomials of degree less than or equal to n forms an n+1 dimensional vector space, idiot
>>10414899
probably read axler, but friedberg is fine too. or hoffman and kunze.

[Anonymous No.10415270]

>>10415255
who cares about those nasty constants?

[Anonymous No.10415300]

>>10415270
(5 + x^3) and (-x^3), as well as "vector spaces are abelian groups with respect to addition," certainly care.

[Anonymous No.10416149]

>>10415071
>Also what applications does it have?
Simplicial stuff, and thus classifying spaces of categories (and therefore groups), and homotopy theory in general. Interesting spaces tend to be geometric realisations of simplicial sets. Also, the cyclic category of Connes, and hence cyclic (co)homology.

[Anonymous No.10416439]

>>10416149
No.
This is like claiming that AG is an application of set theory because "A scheme is a structured set". While technically correct it misses the point entirely. The simplex category can be replaced with most any sifted category and that's precisely because Spc is the free cocomplete category on an object *.
Cyclic homology and cyclic sets are even more of an anti-example: it's precisely the combinatorial nature of the construction which obscures how natural of an operation it is.
At the end of the day, despite the fact that combinatorial widgets are used all over the place in homotopy theory I doubt that any combinatorics papers were cited in the process--and that should speak for itself.

[Anonymous No.10416501]

Where can I get a list of open problems in mathematical physics and/or algebra?
Not like the big ass behemoths. Just new problems that require working out.

[Anonymous No.10416508]

>>10398562
le toopidainlet

[Anonymous No.10416564]

>>10416501
From your advisor.

[Anonymous No.10416572]

>>10416439
Applications are applications, regardless of how reasonable they are.

[Anonymous No.10417077]

>tfw too brainlet for real analysis