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/sci/ - Science & Math


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12203008 No.12203008 [Reply] [Original]

Twistor edition
Talk maths
Antecedent >>12190956

>> No.12203017

>>12203008
A twistor is like a spinor in momentum space. Something like that, I forget the exact transformation.

>> No.12203019

>>12203017
what's a tensor?

>> No.12203022

>>12203017
they said you died or got arrested. took remains unspookable.

>> No.12203028
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12203028

>>12203022
Not only did they say I died, they entered my name into the NatSec table of deceased individuals and have been selling insurance to people with the absolute guarantee that I am a dead man.

>> No.12203037
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12203037

>>12203008

>> No.12203038

>>12203019
A tensor is an object that obeys the tensor transformation law. If you were wondering about a spinor maybe, then a spinor is an object that obeys the the spinor equation.

>> No.12203046

>>12203037
I can't recommend working on this one, mathematics is not ready for such problems. Consider triple integrals instead.

>> No.12203113

>>12203038
very nice
anyone who says a tensor is a matrix is instantly discarded into the pit of dumb

>> No.12203132

>>12203028
wtf? did these claims go through? isn't someone with authority supposed to file that?

>> No.12203137

>>12203017
>>12203019
>>12203022
>>12203028
>>12203038
>>12203113
Piss off schizos

>> No.12203147
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12203147

Some papers that might be of interest to somebody:
>Zeta functions of Lie [math]\mathbb{F}_p[/math]-algebras and finite [math]p[/math]-groups
https://arxiv.org/pdf/2010.02268.pdf
>Group-like Small Cancellation Theory for Rings
(This one looks like a whole book!)
https://arxiv.org/pdf/2010.02836.pdf
>The Steenrod algebra from the group theoretical viewpoint
https://arxiv.org/pdf/2003.14156.pdf
>Wick polynomials in non-commutative probability
https://arxiv.org/pdf/2001.03808.pdf

>> No.12203181

>>12203147
Cheers, lad.

>> No.12203182
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12203182

studying the GRE practice exam. how does C imply invertibility?

>> No.12203235
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12203235

>>12203182
Expand it and you will get [math]I - A + A^2 - \cdots + (-1)^k A^k = 0 \Leftrightarrow I = A - A^2 + \cdots -(-1)^k A^k = A(I - A + A^2 - \cdots -(-1)^k A^{k-1})[/math]. The stuff inside the parentheses is now the inverse of [math]A[/math]. Warning: I may have made a mistake with the signs, but the idea is the same, nevertheless.

>> No.12203238

Lads, please help me: I would be grateful if you could point me in any direction where I can find the (most) information regarding any one graduate school. In a sense, a list of grad schools, their tuition, admission and field of study (analysis, algebra...) etc etc

It's tiring spending a good chunk of my day sifting through university websites trying to find information.

And I'm not talking about master portals, they just give USA, UK and the Netherlands mostly.

Arigato ^___^

>> No.12203241

>>12203235
wack. never seen that before
honestly learning a lot just going through these and finding gaps in my learning, though I suppose that's the point. I should probably stop and run through this exam style properly rather than continue as I am

>> No.12203256
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12203256

>>12203241
I just realised I forgot all the coefficients in the expansion. Remember to get some sleep or else you will do similar mistakes. I knew something was off, but I thought it was the signs. The idea is still the same, as the correct version provides a matrix B such that AB = I = BA. Sorry about that.

>> No.12203297

>>12203147
got anything on stochastics?

>> No.12203302

>>12203008
any guides on induction for recursive sequences?
I cant seem to grasp that shit

>> No.12203391

>>12203238
>Arigato ^___^
is this nigga serious?

>> No.12203417

>>12203235
>I may have made a mistake with the signs
You need binomial coefficients too right? The idea still works though obviously.

>> No.12203418

>>12203417
Oops >>12203256
This is why I should read the thread before posting.

>> No.12203425

Can someone explain why [math] C\rtimes D \cong C*D / \{dcd^{-1}\}_{d\in D, c\in C} [/math]?

>> No.12203717

>>12203182
>>12203235
Another way is to notice that no invertible <=> A has 0 as an eigenvalue.
If Ax = 0 then (I-A)x = x so (I-A)^k x = x so (I-A)^k is not 0.

>> No.12203730

>>12203008
Whats the best book/website for maths problems of all kinds to solve?
I was never one of the "maths people" in highschool; I was above average so I'm looking to better myself now before I start my compsci degree

>> No.12203734

>>12203730
Khanacademy for you.

>> No.12203747

>>12203734
Really? I was expecting some crusty old book lol
thanks I guess
Which course should I stay with? Algebra basics?

>> No.12203757

>>12203747
start* with

>> No.12203761
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12203761

based Sir Roger. awareness of this technique was very useful for me.
https://www.nobelprize.org/uploads/2020/10/advanced-physicsprize2020.pdf

>> No.12203858
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12203858

If a line, or the slope of a line, has the property of 'steepness', what is the term for the corresponding property of curves and derivatives? 'Intensity' seems close but wrong.

For example, how would I describe, in language, the difference between the yellow curve and the red? I could say one is 'flatter' than the other, but that seems to include other properties than what I want.

>> No.12203888

How do I prove [math]\exists \varepsilon>0 [/math] such that [math]\ mypeepee > \varepsilon[/math]?
I'm worried I'm going to have to use imaginary numbers to prove this.

>> No.12203891

>>12203008
If I keep studying mathematics, will I also pick things up about physics along the way?
I'm thinking that I might get a textbook or something with physics problems and see if I can use that to learn more.
I don't want to study physics because I don't really want to work in physics but I still like learning about it, as I find applications for it everywhere.

>> No.12203897

>>12203888
You're not funny, you're not smart, and the trips have been wasted on you. Go back to r*ddit.
I hope you get in a car crash and die.

>> No.12203907
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12203907

>>12203297
Nope, sorry. I took those from my email.

>>12203418
We were both a bit silly, I guess.

>>12203717
Nice one.

>> No.12203919

>>12203858
Curvature is what you're looking for. It's a well researched concept.

>> No.12203934

>>12203919
Perfect, thanks!

>> No.12203943

Would it be weird to enter a zoom/whatever else conference if I'm in another country?

>> No.12203950

>>12203943
No, as long as you're white.

>> No.12203958
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12203958

>>12203943
Why would it be? I attended some German conferences like that.

>> No.12203988

>>12203950
Mr. Moore pls

>> No.12204008
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12204008

>It's 2020 and we still don't know how many real numbers there are
This is getting stupid... At what point do you just give up and admit they're not real?

>> No.12204027
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12204027

Is there any exercises / problem solving book or website that you really enjoyed going through?
Something with actual hard exercises in anything (analysis, algebra, number theory, combinatorics, probability, even algorithms if it's good)..
please recc

I only know Project Euler, but you guys may know something better for mathchads.

>> No.12204030
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12204030

>>12204027
Check out "Linear Algebra Problem Book" by Paul Halmos.

>> No.12204034
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12204034

>> No.12204086
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12204086

>Racism has become the only issue for many Millennials. Even as they ignore how deeply human it is to categorize some fellow humans as the "other", they are doing it themselves to those they believe are racists. They have become totally intolerant of those whom they see as lacking sufficient tolerance.
wtf I didn't know Mumford was based.
http://www.dam.brown.edu/people/mumford/blog/2020/Simple.html

>> No.12204110

>>12204086
You can afford to be based when you've got tenure and you're too old to care anyway
I remember he wrote some pretty interesting blogs in the past too.

>> No.12204167

>>12204034
Third option: put your hands on your ears and pretend it never happened.

>> No.12204202
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12204202

>>12203008
Hello, can someone help me understand fractional indices?

How do I work out the value of something like pic related?

>> No.12204206

>>12204202
FUCK OFF with your kindergarten questions. GO SOMEWHERE ELSE

>> No.12204213

What do you love about math? Was there a moment in your life when you realised something that made you love it?

>> No.12204218

>>12204206
Where am I suppose to go?

>> No.12204219

>>12204213
always been good at it, grew to love it more as I did more and more with it

>> No.12204220

>>12204218
/sqt/

>> No.12204226

>>12204220
>>12204206
Damn, I guess you got filtered by kindergarden math if you can't answer it, lol

>> No.12204242
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12204242

>>12204226

>> No.12204273

Is there a concrete guide for math olympiad prep? Or it's stuff well hidden from commoners?

>> No.12204292

>>12204273
the best people get their prep from teachers who are into highschool olympiads

>> No.12204297

>>12204242

All Mr Filtered

>> No.12204310

>>12204273
>Is there a concrete guide for math olympiad prep?
step 1, ignore olympiad shit
step 2, study actual math

>> No.12204316

>>12204292
The problem with this reasoning is that to become "best", you have to get an adequate prep first.

>> No.12204322

>>12204030
will check it out, thanks

>> No.12204326

>>12204310
If you can't solve olympiad problems, then you are wasting time by doing math.

>> No.12204329

>>12204326
By that logic like half the number theorists in Australia should have their tenure revoked.

>> No.12204352

>>12204326
>if you dont have 3 dozen different identities memorized from areas of math you dont work in, then you are wasting time by doing math
when was the last time you did a geo problem outside of a fucking olympiad

>> No.12204358

>>12204352
I do some basic geometry when I teach calculus I guess.

>> No.12204442

>>12204352
Ask this a physicist or an engineer.

>> No.12204477
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12204477

>>12204329
>TERRY!
>TERRY GET THE FUCK OUT HERE!
>>Oh geeze whats going on?
>GET IN THE CAR TERRY
>GET IN THE FUCKING CAR!
>>Oh geeze I was having a sleep, I was having a little Tao sleep, working on the Schrö-
>TERRY, GET IN THE DAMN CAR NOW
>>ohhhh why?
>WE'RE GOING TO BINDEGO TO GET ME ROBIN'S THEOREM
>WE'RE GONNA PROVE THE RIEMAN HYPOTHOSIS TERRY
>>oh geeze...

>> No.12204493

>>12204358
>>12204442
Olympiad Geometry, not analytical geometry
im talking about similar triangle bullshit
theyre not even related to the geo that physicists or engiees do
fucks sake, its obvious from context what kind of geo im talking about

>> No.12204497

>>12203730
Khan has a lot. Brilliant gets shilled a lot but is apparently quality.

>> No.12204501

>>12204497
>Brilliant
I tried a free trial by them once, but it seems to me as if their lessons are aimed at the lowest common denominator, is this incorrect?

>> No.12204602

>>12204493
You are just a kind of person who haven't dealt with mathematical problems, otherwise you'd know that translating everything into coordinates is not always the best way to go.

>> No.12204625

>>12204602
>otherwise you'd know that translating everything into coordinates is not always the best way to go.
wow cool, its almost like thats not what we're talking about
also
>haven't
you mean hasn't ESL retard

>> No.12204680

>>12204493
>there's no similar triangle bullshit in calc classes

>> No.12204692

>>12204625
There's nothing wrong with being an ESL.

>> No.12204722

>>12204213
I watched vsauce

>> No.12204784

>>12204213
I went blind into math because engineering seemed boring. I didn't even liked it until third semester when I had a cool teacher for Linear Algebra I.

>> No.12204809

>>12204784
I went into math. Linear algebra was fucking terrible for me, an absolute slog through boring material. Abstract algebra and its secondary grad level classes were my favorite classes during my entire undergrad.

>> No.12204868

>>12204213
When I had my first class about modular arithmetics in high school, and had to make proofs for the first time.
Before that I wanted to become a doctor, but I decided I just wanted to learn more maths instead

>> No.12204928

>>12204202
The n-th root of x is another way of writing x to the power 1/n. From there you should be able to find out to use them, it follows standard rules.

>> No.12205077

>>12204027
anyone else got any suggestions?

>> No.12205134
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12205134

>>12205077
Thank me later.

>> No.12205147

>>12204202
x = nth root of y means x=y^(1/n) which means x is the solution of the equation x^n-y=0, which can be solved numerically by algorithms like newton-raphson, bisection, regula falsi, and the Illinois algorithm.

>> No.12205181

>>12205134
is that really an exercise book? seems like a good read nevertheless.

>> No.12205228

>>12205181
Not strictly, but it has lots of good problems in it.

>> No.12205629

>>12203113
Anyone who says anything but a multilinear map of the elements of the vector spaces and their duals is is instantly discarded into the pit of dumb.

>> No.12205744
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12205744

>>12203235
>expand it
What do you mean expand it?
[math]\frac{1}{1 - x} = \sum _{k = 0}^{\infty} x^ k[/math]. By the same token, [math]\frac{I}{A} = \frac{I}{I - (I-A)} = \sum _{k = 0}^{\infty} (I-A)^ k[/math]. The sum terms eventually zero, so the series converges and you get an inverse.

>> No.12205796
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12205796

Anyone know some good math books for soft reading? I was looking at, "Mathematics and Its History" for example.

>> No.12205827

I need help with alg
Given a [math]k[/math]-cycle in [math]S_n,\ \sigma[/math], with [math]2\leq k\leq n-2[/math] I want to show that the centralizer [math]C(\sigma)[/math] is the product of two nontrivial groups.
The obvious isomorphism is [math]C(\sigma) \cong \langle\sigma\rangle \times S_{n-k}[/math], given by the normal composition where [math]S_{n-k}[/math] is the collection of permutations disjoint to [math]\sigma[/math]. but I'm stuck on the final part of showing it's iso. I need help showing that every element of the centralizer is a product of a power of [math]\sigma[/math] and something disjoint to [math]\sigma[/math].
Any ideas?

>> No.12205984

If [math]g: A\to B[/math] is a continuous open map such that [math] B[/math] is Hausdorff and connected, why is [math]g[/math] surjective? It's clear that [math]g(X)[/math] is open. It's not clear to me that [math]g(X)[/math] is closed.

>> No.12206046

>>12205984
wouldn't [math]g:A\rightarrow B[/math] being surjective imply [math]g(A)[/math] is open and closed and not necessarily [math]g(X), X\subset A[/math] being open and closed?
[math]g(A)[/math] being open and closed seems intuitive at least, so if that's how it works there you go.

>> No.12206055

>>12206046
Oops I made a mistake. I meant to say [math]g(A)[/math] instead of [math]g(X)[/math]. Anyways, the point being that I want to prove that [math]g(A)[/math] is both open and closed which would then prove that [math]g(A)[/math] is surjective as the only subsets of a connected space that are open and closed are the space itself and the empty set. Proving that [math]g(A)[/math] is open is really easy. I'm stuck on trying to prove that [math]g(A)[/math] is a closed set.

>> No.12206065

>>12205629
>elements of the vector spaces
But anon what about [math]R[/math]-algebra tensors?

>> No.12206331

>>12203113
The transformation law meme is a complete brainlet take for physicists.

>> No.12206334

>>12206065
Algebras over a ring have underlying modules, of which you can take tensor products.

>> No.12206336

>>12206055
>>12205984
Doesn't that whole arrangement imply [math]A[/math] is connected as well?
[math]g^{-1}(B)=\text{clopen}[/math] and [math]g^{-1}(\emptyset)=\text{clopen}[/math] follow from the closed and open definitions of continuity? Then [math]A[/math] and [math]\emptyset[/math] are the only clopen subsets of [math]A[/math] and [math]g(A)[/math] is one of [math]\emptyset[/math] or [math]B[/math] and therefore has an open complement.
Been a while since I skimmed a topology book but is that right?

>> No.12206442

>>12206334
If I'm interested in the universal property (cofibred product) as ring algebra tensors then I have to do a fair bit of work to get there from a definition of tensors of [math]R[/math]-modules. It turns out there are multiple useful descriptions!

>> No.12206564

>>12204086
Based mumford

>> No.12206568

Question is "Find 3 subset A, B, C to set E such that A, B, C, A∩B"

How do you even read A, B, C, A∩B? What do the commas represent? Thank you /sci/

>> No.12206631

>>12203182
The answer is (E) right? Because even if Av_i is not zero, it could map all three vectors to a proper subspace of R^3? Just want to make sure I haven't forgotten my linear algebra.

>> No.12206640

>>12205629
anyone who doesn't mumble something about monoidal categories is instantly discarded in the pit of dumb

>> No.12206808

>>12206631
yeah, it's E

>> No.12206846

In Ontatio, Canada we have a 90 credit BSc./BA. degree and a 120 credit Honours BSc./BA. degree. I'm currently in the 90 credit BSc. Applie Math degree. A 120 Hons. BSc/BA is required for grad school. For anyone familiar with this distinctiin, what are my job optics if I stick with the 90 credit degree?

>> No.12206851

>>12206846
kings honor friend

>> No.12206857

>>12206851
??

>> No.12206864

>>12206846
There is a few factors I would consider.

Do you have the capital to sustain yourself and go to school and get the honors degree as compared to the regular one? Also, are you young? I would say the honors program will probably lead to an increased career outlook, as a rule, but if you can't afford it or are too old it may not be worth it.

>> No.12206939

>>12203425
yes

>> No.12206942

>>12203907
Is it a public mailing list? Can I add my email?

>> No.12206954
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12206954

>>12205744
>What do you mean expand it?
Yes.

>>12206942
Follow these instructions. https://arxiv.org/help/subscribe

>> No.12206988

>>12203182
>>12203235
>>12203717
Did you guys figure this out just now, or have you seen something similar before?

>> No.12206994

>>12206988
Figured it out when I posted it. Haven't seen it before (third one you're replying it).

>> No.12206996
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12206996

>>12206988
I'm specialised in algebra stuff, so I sometimes do similar tricks to get inverses.

>> No.12207004
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12207004

>It's October 8, year of our Lord 2020, and we still don't know how many real numbers there are

>> No.12207042

The long ray is comprised of an uncountable number of [0,1) segments laid end to end.

Does it have a first segment? Does it have a second segment? If so, why aren't the segments countable?

>> No.12207045

>>12207004
[math]\mathfrak{c}[/math]

>> No.12207051

>>12207045
Oh wow you gave a letter to the size. Now what?

>> No.12207055

>>12207042
>Does it have a first segment? Does it have a second segment?
Yes, yes.
>If so, why aren't the segments countable?
Because you defined it so they aren't. (uncountable number of [0,1))

>> No.12207056

>>12207004
[math]\infty[/math] times two, duh.
one for the positives, one for the negatives.

>> No.12207058

>>12207051
It can be bounded.
[math]|\mathbb{N} |\leq \mathfrak{c} \leq \aleph_{1} [/math]

>> No.12207062

>>12207055
Then the definition is inconsistent and the long ray doesn't exist.

>> No.12207063

>>12207058
Sorry, the first [math]\leq[/math] should just be <

>> No.12207064

>>12207058
We know c is bigger that |N|, so you're saying that c= aleph_1.
Where can I find a proof of this?
>>12207062
>Then the definition is inconsistent
How so?

>> No.12207073

>>12207064
If the long ray exists you can use the same construction on the number of digits in decimal representations of numbers to construct an uncountably irrational number with uncountably many digits.
No such number exists, as all decimal representations are countable.

>> No.12207076

>>12207064
I'm not saying that [math]\mathfrak{c} = \aleph_{1}[/math], I'm saying that [math]\mathfrak{c} \leq \aleph_{1}[/math].

>> No.12207080

>>12207073
>If the long ray exists you can use the same construction on the number of digits in decimal representations of numbers to construct an uncountably irrational number with uncountably many digits.
How? What is the construction?

>> No.12207088

>>12207076
but aleph_1 is the smallest uncountable cardinal

>> No.12207090

>>12207080
Take a segment [0,1). Append another [0,1) to the right hand side. Do this such that the numbers of segments is in bijection with [math]ω_1[/math].
Substitute segments with digit places.

>> No.12207094

>>12207088
Oh. I'm retarded.
Should be [math]\aleph_{1} \leq \mathfrak{c}[/math]

>> No.12207097

>>12207090
>Do this such that the numbers of segments is in bijection with ω1ω1.
I'm not sure you know what you mean by that. This is not a rigorous construction.
>Substitute segments with digit places.
Lol what?

>> No.12207099

I hate this fucking board.

>> No.12207104

>>12207099
What don't you like about it?

>> No.12207176

>>12206568
Did the subgroup poster started a competition for the stupidedt question asked in the history of /mg/?

>> No.12207182

>>12207176
Certainly looks like it.

>> No.12207206
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12207206

>>12206568
[math]\forall C: A\cap B[/math] viva la involucion!

>> No.12207237

>made no progress so far the entire week
>feel like absolute shit
>have to meet my advisor tomorrow
What the fuck do I tell her, /mg/

>> No.12207242
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12207242

>>12207237
Same but 3 weeks. I tell mine of all the stupid ideas I had and was unable to take to the end or turned out to be stupid after checking the details.

>> No.12207247
File: 335 KB, 500x744, 1600197706488.png [View same] [iqdb] [saucenao] [google]
12207247

>>12207242
Not bad, I will do that as well. I knew it was a good idea to consult /mg/

>> No.12207530

>>12207004
[math]2^{\aleph_0}[/math]

>> No.12207608

>>12203008
Is the empty set a member of the complement of the empty set?

>> No.12207611

>>12207608
No. The complement of the empty set is not a set.

>> No.12207619
File: 22 KB, 1039x787, redard.png [View same] [iqdb] [saucenao] [google]
12207619

someone explain to me how picking contours in the complex plane somehow magically allows us to solve real integrals

>> No.12207623

>>12207530
Right, it's also
[math]\aleph_0 ^{\aleph_0} = 3^{\aleph_0 }= 1000^{\aleph_0 }=\aleph_0 ^ {\aleph_0 \times \aleph_0 }[/math]
There are infinitely many ways to express it. That doesn't tell you how big it is.
The question is for which k, [math]\aleph_k = 2^{\aleph_0}[/math]

>> No.12207626

>>12207623
k=2.3

>> No.12207630

>>12207626
Aleph_k is only defined for ordinal values of k. What do you mean by aleph_2.3?

>> No.12207631
File: 367 KB, 750x698, Picturememe.jpg [View same] [iqdb] [saucenao] [google]
12207631

What area of math is the most poggers?

>> No.12207632

>>12207611
Specify a universe before taking complements, heathen. It's like you don't even know about restricted comprehension.

>> No.12207639

>>12207632
Bro it's perfectly fine to form general sets {x: P(x)} as long as P(X) does not involve x containing itself (or logically reducible to x containing itself)

>> No.12207642

>>12207630
[math]\aleph_2<2^{\aleph_0}<\aleph_3[/math]

>> No.12207648

>>12207642
That's provably impossible because by definition Aleph_3 is the smallest cardinal that's bigger than Aleph_2.

>> No.12207649

>>12207619
The integral over the big semicircle is basically zero.

>> No.12207653

>>12207648
Sorry, spend a few more decades studying, then you might get to the level where you can understand this

>> No.12207655

>>12207653
Ok thanks for the help bro

>> No.12207657

>>12207655
yeah no worries bro

>> No.12207658

>>12207639
No it's not, just take P(x) to be any statement which is always true, like 1=1.

>> No.12207676

>>12203008
>Twistor edition

One comment about twistors that's vaguely right, the rest are shit posts about basic math. This sums up everything that's wrong about /sci.

>> No.12207695

>>12207658
So you get the set of everything.

>> No.12207715

>>12207623
Set theory fag here, for any uncountable ordinal [math]\alpha[/math], it is consistent with ZFC that [math]\aleph_{\alpha}=2^{\aleph_0}[/math]. This is called Easton's theorem.

>> No.12207726

>>12207676
And the vaguely right thing was some schizo mindlessly repeating something he heard on a YouTube video. At least there's no race bait yet.

>> No.12207733

>>12207715
Woops, I had a brainfart, I meant to say it is consistent with ZFC that [math]\aleph_{\alpha}=2^{\aleph_0}[/math], where [\math]\aleph_{\alpha}[/math] has uncountable cofinality. In particular the continuum cannot be [math]\aleph_{\alpha}[/math], where the cofinality of [math]\alpha[/math] is countable.

>> No.12207735

>>12207695
There is no such thing. Its existence would contradict Cantor's theorem.

>> No.12207872

>>12207653
Based.

>> No.12207933

how do I learn proofs by induction?
I kinda slacked off in my uni course and the learning curve got very steep very fast and I have no idea what's happening and how to approach the problems

>> No.12207958

>>12207933
First you learn a basic proof, then you imagine that you've learned the first n proofs in the class. If you can use that to learn the (n+1)st proof in the class you've learned proofs by induction.

>> No.12207975

>>12207933
Prove Laplace expansion and Cauchy's integral formula by induction.

>> No.12207989
File: 81 KB, 1280x720, ffkf.jpg [View same] [iqdb] [saucenao] [google]
12207989

>>12207933
Do you understand the basic idea? You have a claim that is somehow related to the natural numbers. First you show it is true in the case where n is the smallest allowed natural number. Then you want to show that if it holds for some k, then it will hold for k+1. This is done by assuming that it is true for k, and this assumption is the induction hypothesis. Once you have done these two, you will get it for all (allowed naturals), as being true for the smallest OK number implies truth for the next one, and that will then imply truth for the one after itself etc. And what I mean by allowed/OK is that you don't necessarily start from 0, for example [math]n! > 2^n[/math] is true for [math]n \ge 4[/math].

>> No.12208022

>>12207989
I know the idea but I can never come up with the solutions on my own because there doesn't appear to be a consistent way, it feels like you have to guess or come up with bullshit ideas

>> No.12208043
File: 61 KB, 1096x720, a6hz7.jpg [View same] [iqdb] [saucenao] [google]
12208043

>>12208022
Can you do babby's first induction proof, that is [math]\sum\limits_{i=0}^n = \frac{n(n+1)}{2}[/math]? If not, show us (or me) where you get stuck. Otherwise, give some other problem you are stuck with and point out where you get stuck.

>> No.12208050

>>12208043
Lol induction is such a weird way to prove that.

>> No.12208059

>>12208050
It's the best way to do it.

>> No.12208060

>>12207715
>it is consistent with ZFC that
Means we need more axioms.

>> No.12208072

>>12208043
[math]\frac{(n+1)(n+2)}{2}=\frac{n^2 + 3n + 2}{2}=\frac{n^2+n+2n+2}{2}=\frac{n(n+1)}{2}+(n+1)[/math]
is this what i was supposed to do?

>> No.12208071

>>12208059
2(1+2+3+...+n)=
1 + 2 + 3 + ... + n +
n + (n-1) + (n-2) + ... + 1 =
(n+1) + (n+1) + .. + (n+1) =
n*(n+1)

>> No.12208107
File: 94 KB, 700x880, 3r23.jpg [View same] [iqdb] [saucenao] [google]
12208107

>>12208050
It's also the usual first induction problem in your HS book/uni intro course, at least judging by what I have seen.

>>12208072
If you would actually follow the steps you claimed to know, you would first say it is true for 0 because the sum of the first 0 naturals is 0, and on the other side of the sign you would have 0/2 = 0. Then you would assume it holds for some k and do [math]\sum\limits_{i=0}^{k+1} i = \sum\limits_{i=0}^k i + (k+1) = \frac{k(k+1)}{2} + k+1 = \cdots = \frac{(k+1)(k+2)}{2}[/math], where the skipped part is what you did but backwards. Your thing doesn't prove the claim because it is not related to anything. You are not connecting [math]\frac{n(n+1)}{2}[/math] to the sum in any way, only showing that you can write the leftmost term like you have on the far right. Write more!

>> No.12208112

>>12207735
Power set axiom only holds for small sets.

>> No.12208122

>>12208107
I want to fuck you in the ass.

>> No.12208128

>>12208107
yeah I omitted the first step because it seemed obvious and not needed
I have a problem which I have no idea how to approach though, it follows:
Prove by induction that all numbers greater or equal to 8 can be expressed as a sum of 3s and/or 5s. E.g. 8 = 3 + 5, 9 = 3+3+3

>> No.12208141

>>12208128
>yeah I omitted the first step because it seemed obvious and not needed
Get in the habit of writing out your proofs in full.
Doesn't matter that you find certain steps obvious. Writing them out in full will make your learning process much faster and let you think more clearly.

>> No.12208172

>>12208141
I will do that. Do you have any clues for that problem?

>> No.12208182

>>12208112
That's not a healthy way to live.

>> No.12208200

>>12205744
>The sum terms eventually zero, so the series converges
not how convergence works
also not what they're looking for, it needs to terminate after finite [math]k[/math] and never does it say you get to sum the [math](I-A)^k[/math]. there needs to be a [math]k[/math] such that [math](I-A)^k=0[/math], that's it

>> No.12208460

>>12208128
Idk if this is a correct type of approach, but what do you think of this observation?

Consider a particular sum of 3s and/or 5s.
If the sum has at least two 3s in it, then you can replace the two 3s with a 5 and effectively subtract 1.
If it has at least two 5s, you can replace the two 5s with three 3s and subtract 1.
After either operation, the result will still be a sum of 3s and 5s.
Any (integer) sum of 3s and 5s greater than 8 will also itself have at least two 3s or two 5s.
So you can get to any particular number >=8 by just picking some greater number that is a sum of 3s and 5s, and counting downward in this manner until you reach the desired number.
So for any integer of the form 5a+3b, you can prove by induction that all smaller integers >=8 must also be representable in that form.
You can also count upward if you prefer, maybe most simply by just adding one three and then decrementing twice.

>> No.12208510

>>12208172
Yes. 1 = 2(3)-5. So if n can be expressed as a sum with at least one 5, you can express n+1 with 2 more 3s and 1 less 5.
If there are no 5s in n, then assuming n>=10 you can replace 5*2 with 2*5. Voila.

>> No.12208542

>>12205796
Geometry and imagination by Hilbert. Great book.

>> No.12208548

Sometimes I think of instead of pursuing a PhD at a university, I NEET with my parents at home and try to study and achieve results on my own.

>> No.12208589

>>12208060
The whole program of relative consistency proofs are predicated on the assumption that the base theory is consistent. All we are do to prove Easton's theorem is show that if ZFC has a model, then ZFC+ Easton's theorem has a model. This is one of the finer points of forcing. Kunen gives a great explanation on this.

>> No.12208614
File: 91 KB, 1280x720, sopkwq.jpg [View same] [iqdb] [saucenao] [google]
12208614

>>12208122
Maybe some day but not now, sorry. Unless you kill my bf to claim me first, but he is a big engineering chad with military training.

>>12208128
When you begin with proofs, you should basically write a novel every time you prove something. When you get the so called maturity, you can drop the more obvious parts and make more fancy proofs.

>> No.12208750
File: 875 KB, 5111x3407, emco.jpg [View same] [iqdb] [saucenao] [google]
12208750

>>12205796
This book is fantastic
https://books.google.at/books/about/Modern_Algebra_and_the_Rise_of_Mathemati.html?id=WdGbeyehoCoC&redir_esc=y

>Leo Corry - Modern Algebra and the Rise of Mathematical Structures


>>12206988

[math]f(x)-c\cdot f'(x) = g(x)[/math]

So clearly
[math] \implies f(x) = \dfrac{1}{1-c\cdot \frac{d}{dx}}g(x) = g(x) + \sum_{n=1}^\infty c^n \left(\frac{d}{dx}\right)^n g(x)[/math]

You can make some of it also work with [math] \dfrac{1}{1-c\cdot \int^x dt}[/math]

>> No.12208778
File: 13 KB, 505x285, 1111.png [View same] [iqdb] [saucenao] [google]
12208778

Could someone explain to me what rule is used when the excluded third party law is set?
The related pic is the formal proof of the absorption law, but I don't understand why Q can be removed from the material implication.

>> No.12208832

>>12208778
You can introduce assumptions, but you can introduce tautologies, and LEM is a tautology (classically).

>> No.12208878

>>12207619
An integral of an analytic function over a closed contour in C is zero. If the function is analytic except for at finitely many points then the residues at those points are the only contribution to the integral. Combine this with analytic continuation on exp(x) to exp(z) and you're 90% there.

>> No.12208892

>>12208778
p a r t y

As that other anon said, step 3 doesn't follow from 2 but is introduced here in axiomatic fashion

>> No.12208903

>>12208892
>>12208832
Thanks for your answers, I did not remember that the excluded third was an axiom and confused it with a rule of inference.

>> No.12208930
File: 36 KB, 207x390, 42357675.jpg [View same] [iqdb] [saucenao] [google]
12208930

>>12208903
You are welcome. I remember trying to do deductions like that back in the days and forgetting all the introduction and elimination rules. It was painful.

>> No.12208989

>>12208614
how do you get a chad engineering bf?

>> No.12209072

>>12208878
Is there a better theorem in CA?
https://proofwiki.org/wiki/Cauchy-Goursat_Theorem

>> No.12209146

>>12208750
Not him but sounds neat

>> No.12209230
File: 30 KB, 225x350, 48457.jpg [View same] [iqdb] [saucenao] [google]
12209230

>>12208989
Talk to nice guys online and maybe you will find one.

>> No.12209279

If A is a subset of B and C is a subset of B then are A and B subsets of each other?

>> No.12209312

>>12209279
Based average /mg/ poster

>> No.12209327

>>12209279
no C is a normal subgroup of A X B

>> No.12209417

>>12203717
Very nice, went the idempotent route

>> No.12209421

>>12208043
Hello fellow based Gabu poster

>> No.12209489 [DELETED] 
File: 1020 KB, 1396x1134, weebgirl.png [View same] [iqdb] [saucenao] [google]
12209489

If [math]a[math] divides [math]b[math] and [math]c[math] divides [math]b[math], do [math]a[math] and [math]c[math] divide eachother?

>> No.12209490

>>12209421
Cheers, lad.

>> No.12209494
File: 1020 KB, 1396x1134, weebgirl.png [View same] [iqdb] [saucenao] [google]
12209494

If [math]a[/math] divides [math]b[/math] and [math]c[/math] divides [math]b[/math], do [math]a[/math] and [math]c[/math] divide eachother?

>> No.12209563
File: 39 KB, 640x634, 9vvj7.jpg [View same] [iqdb] [saucenao] [google]
12209563

>>12209421
Hi.

>> No.12209566

>>12209494
no
>>/sqt/

>> No.12209576

>>12209494
>i-is this bait

Counterexample: any prime factorization

>> No.12209601

>>12209494
sometimes

>> No.12209689

>>12208589
Then why does Woodin think CH has a definite value? Is he not aware of Easton's theorem?

>> No.12209696
File: 30 KB, 402x401, 1470908160161.jpg [View same] [iqdb] [saucenao] [google]
12209696

>>12209494
>>12209279
FUCKING STOP

>> No.12209744

>>12209689
Easton's theorem just classifies what cardinals the continuum can be over ZFC. You can use it to make CH true for instance. I don't understand V=Ultimate L (his current conjecture) very well, if at all, that is not my field of set theory. One thing though, basic Cohen forcing over L will violate CH. My very basic understanding is that CH holds in Ultimate L and Ultimate L only has trivial forcing extensions. So you can't break CH with forcing. Of course the existence of Ultimate L is a only conjecture and could be very wrong. But there is evidence, we'll have to wait and see. I think Woodin has lecture about it youtube if you're interested.

>> No.12209838

>>12209744
>I don't understand V=Ultimate L (his current conjecture)
I don't know why those guys call those things conjecture.

Sounds like
>strawberries is the best ice cream
kind of conjectures to me

>hat is not my field of set theory
what is

>> No.12209878

If [math]a \leq b [/math] and [math] c \leq b[/math] does [math]a = c[/math]?

>> No.12209924

>>12209838
I guess the language is a little imprecise. The conjecture is that Ultimate L exists. The proposal for the new axiom to add to ZFC would be V=Ultimate L. My field is descriptive set theory, this stuff falls under inner model theory.

>> No.12210015

>>12209878
Not necessarily.

>> No.12210081

If [math]A \implies B[/math] and [math] C \implies B [/math] is it true that [math]A \iff B[/math]?

>> No.12210199

If [math]n=2k>2[/math] with [math]k/in/mathbb{N}[/math] then [math]n=p+q[/math] with [math]p,q[/math] primes?

>> No.12210224

>>12210081
Not necessarily.

>> No.12210237

>>12209878
Just compute a counter-example

>> No.12210248

Suppose [math] G[/math] is a directed graph and [math]v_1,v_2,v_3[/math] are vertices of [math]G[/math]. If there is a path from [math] v_1 [/math] to [math] v_2 [/math] and a path from [math] v_3 [/math] to [math] v_2 [/math] are there paths from [math] v_1 [/math] to [math] v_3[/math] and vice versa?

>> No.12210294

>>12210248
Let [math] \mathcal{C} [/math] be any category. Suppose [math] \mathscr{F}, \mathscr{G}, \mathscr{H} [/math] are representable functors [math]\mathcal{C} \to \text{Set}[/math]. Suppose there exist natural transformations [math]\mathscr{F} \Longrightarrow \mathscr{G} [/math] and [math]\mathscr{H} \Longrightarrow \mathscr{G} [/math]. Does there exist a natural isomorphism [math]\mathscr{F} \cong \mathscr{H} [/math]?

>> No.12210303

>>12210248
Not necessarily. There is an extremely simple example with only 3 vertices, see if you can come up with it.

>> No.12210375
File: 20 KB, 581x397, Screenshot (14).png [View same] [iqdb] [saucenao] [google]
12210375

>>12210303
?

>> No.12210755

>>12209878
>>12209494
>>12209279

Based

>> No.12210789

>>12210755
What about
>>12210248
and
>>12210294
?

>> No.12210800
File: 46 KB, 437x501, a58941a2f66c4857b3fc962c798c40d8fe7df0155f14733260fd8cdb4acb0887.jpg [View same] [iqdb] [saucenao] [google]
12210800

>>12203008
I have done it. I derived the feigenbaum constant from the monster group. I also derived the monster group from the feigenbaum constant. Mathematics is over. Where do I publish this? Should I make a youtube video?

>> No.12210805

>>12210800
When you say derived what exactly do you mean? What is the relationship?

>> No.12210823

>>12210800
How many pitchforks did you have to look at?

>> No.12210843
File: 193 KB, 2156x2941, steg0.jpg [View same] [iqdb] [saucenao] [google]
12210843

I am supposed to do a Gauss-Newton on a set of datapoints but one of the datapoints is approaching inf. Do I just drop it?

>> No.12210934

>>12210081
what is C?

>> No.12210944

If I have a weak homotopy equivalence [math]X \to Y[/math] and a weak homotopy equivalence [math]X \to Z[/math], then does there exist a weak homotopy equivalence [math]Y \to Z [/math]??

>> No.12210971

>>12210934
A type in the first universe.

>> No.12210980
File: 368 KB, 943x997, x_vals.png [View same] [iqdb] [saucenao] [google]
12210980

What are some nice 2D manifolds that I can easily calculate geodesics for? I'm messing around trying to render 2D manifolds from geodesics. Pic related is the 2-sphere.

>> No.12211046
File: 823 KB, 4032x3024, PICCPCICIC.jpg [View same] [iqdb] [saucenao] [google]
12211046

How do I solve this? I dont know what the A, B and C is.

Please help me.

>> No.12211057

>>12210980
cylinder

>> No.12211070

>>12211046
Sorry bro, no applied maths here

>> No.12211072

>>12211046
I haven't read your question or picture, but the answer is always
A=C

>> No.12211129
File: 8 KB, 943x997, y-value.png [View same] [iqdb] [saucenao] [google]
12211129

>>12211057
It turns out easy to understand 2D manifolds are pretty boring.
I'm not sure geodesic rendering would work in real time. It's a shame because most games on manifolds just use charts and try to hide the transitions which is really boring imo.

>> No.12211144

>>12211129
Actually this paper seems to do exactly what I want: https://arxiv.org/abs/2002.09533
>We present novel methods of computing real-time native geodesic rendering of non-isotropic geometries

>> No.12211308

>>12209689
>>12209744

Which of those should I read (first)?

>In Search of Ultimate-L the 19th Midrasha
Mathematicae Lectures.
http://logic.harvard.edu/EFI_Woodin_StrongAxiomsOfInfinity.pdf

>Strong Axioms of Infinity and the search for V
https://dash.harvard.edu/bitstream/handle/1/34649600/59799476.pdf

>> No.12211329

What are some ways in which rings can be extended to a field?
Are there canonical techniques?

>> No.12211346
File: 136 KB, 1920x1389, af0uz.jpg [View same] [iqdb] [saucenao] [google]
12211346

>>12211329
The obvious one is the field of fractions for an integral domain.

>> No.12211357

>>12211346
thx

>> No.12211358

>>12211329
If your ring is an integral domain, then you can extend it to the so-called field of fractions which is the "smallest" field that contains your ring (up to isomorphism). If it is not an integral domain you cannot extend it to a field because every subring of a field is an integral domain

>> No.12211361

>>12211358
thx thx

>> No.12211372
File: 30 KB, 700x373, foo.jpg [View same] [iqdb] [saucenao] [google]
12211372

>>12211358
If [math]C[/math] is a field and [math]A\subset C[/math] an integral domain, is the field of fractions [math]B[/math] of [math]A[/math] a subfield of [math]C[/math]?

>> No.12211385
File: 544 KB, 953x1055, corti.png [View same] [iqdb] [saucenao] [google]
12211385

Assuming Choice, is the cardinality of the field of fractions of an infinite ring always the same as that of the ring?

>> No.12211404
File: 171 KB, 2132x2168, aapav.jpg [View same] [iqdb] [saucenao] [google]
12211404

>>12211385
Let [math]Q[/math] be the field of fractions of an integral domain [math]R[/math]. Then [math]|R| \le |Q| \le |R| \times |R|[/math], so it will be the same in the case [math]R[/math] is infinite. If [math]R[/math] is finite, then it is a field already, and so it is its own field of fractions. The answer is yes.

>> No.12211420

>>12211404
Okay, looks good.

I didn't ask for the finite part but I also don't get it. Why is a finite integral domain already a field?

>> No.12211436
File: 94 KB, 855x987, a3nbc.jpg [View same] [iqdb] [saucenao] [google]
12211436

>>12211420
Oops I somehow skipped the "infinite" in your post. A quick proof can be found for example here http://www-groups.mcs.st-andrews.ac.uk/~john/MT4517/Lectures/L4.html (scroll down a bit but not too much).

>> No.12211496

>>12211372
Yes, that is what is meant with "smallest". The field of fractions [math] F[/math] of an integral domain [math]A [/math]satisfies the following universal property. If [math]K [/math] is a field and [math]f: A \to K [/math] an injective ring homomorphism, then there is a unique homomorphism [math]F \to K[/math] (which is also injective) extending [math]f [/math]. This property characterizes F up to canonical isomorphism

>> No.12211534

If A, B, C are G-modules with finite cohomology groups, A is a submodule of C and B is a submodule of C, does that imply A is a submodule of B?

>> No.12211577

>>12211534
We should write a Bourbaki style tome that restates all theorems of mathematics in this form.

>> No.12211636

>>12211308
What's your background?

>> No.12211658

>>12211636
I donno, I should be able to read those more or less, I hope

>> No.12211677

Any russian anons here? What do you think of Independent Moscow University?

>> No.12211692

>>12203730
Paul's Online Notes has a lot of practice problems and is an excellent reference guide/textbook for the standard Calculus I, II, III series plus diffeqs.

>> No.12211695

>>12208614
Are you a tranny or an actual woman?

>> No.12211702

>>12211658
The first one is a brief survey paper. If you know about L and large cardinals you should be fine. The second one I wouldn't even touch if you don't know how extender models work.

>> No.12211705

>>12211702
okay, good to know

>> No.12211707

Any Cambridge chads here? I'm a third year mathmo.

>> No.12211737

How do you guys read through textbooks for fun? Do you read them as you do literature or do you have a notebook and take notes as if for a course?

>> No.12211740

https://en.wikipedia.org/wiki/%CE%98_(set_theory)

>> No.12211801
File: 98 KB, 900x506, 9yrgf.jpg [View same] [iqdb] [saucenao] [google]
12211801

>>12211695
Yes.

>>12211737
If there are exercises, then I try to do those at least in my head.

>> No.12211807

>>12211801
>tranny
>Madoka poster
How does it feel being a living meme?

>> No.12211823

>>12211737
I never take notes. But I really can't read math books as literature. I keep pen and paper next to me to work through proofs, examples, some exercises, etc..

>> No.12211829

>>12211737
unless you're an absolute god of mathematics you should definitely take notes otherwise you just won't retain anything imo

>> No.12211832

>>12211829
>he doesn't just commit everything to memory after reading it one time
do brainlets really...?

>> No.12211842

>>12210789
also based. I only skimmed over the thread. The real question is: [math]f\in L^{a}, g\in L^{b}, c=a+b, \text{ is } g+f\in L^c[/math]?

>> No.12211893

Does anyone feel like the math and humanities part of their brain excludes one another? I find that when I’m studying math intensely, I have very little patience for consuming literature / films and am less interested by the arts in general. I only really think about math. And if I take a break from study, the exact opposite occurs. I’ve also noted that most of my math professors are culturally quite dumb (i.e. watch anime, have basic political opinions, etc.). Is there something about focusing your brain on high level analytical concepts that distances you from other kinds of thinking? Obviously this wasn’t always the case (e.g. all the polymaths in history of mathematics) but wonder if this is a side effect of hyperspecialization.

>> No.12211947
File: 119 KB, 695x715, 40v0l.jpg [View same] [iqdb] [saucenao] [google]
12211947

Some papers for you today
>Measure equivalence classification of transvection-free right-angled Artin groups
https://arxiv.org/pdf/2010.03613.pdf
>New approaches for solving linear confluent Vandermonde systems and inverse of their corresponding matrices via Taylor's expansion
https://arxiv.org/pdf/2010.03862.pdf
>The derived-discrete algebras over the real numbers
https://arxiv.org/pdf/2010.03787.pdf
>Simplicial Neural Networks
https://arxiv.org/pdf/2010.03633.pdf

>>12211807
Pain is temporary but glory is... who am I kidding? Pain is eternal.

>> No.12212107

>>12211947
Thansk

The abstract of the NN paper for ML fags is funny

>> No.12212371

what the fuck is this algebraic topology holy shit

>> No.12212386

>>12212371
a meme

>> No.12212390

>>12212371
a subject that has been completely rewritten at least 2 times

>> No.12212524

Are there any books for algebra like 'Counterexamples in Analysis' by Gelbaum & Olmsted and 'A Problem Book in Real Analysis' by Aksoy & Khamsi?

>> No.12212790
File: 161 KB, 1190x607, 2020-10-09-233834_1190x607_scrot.png [View same] [iqdb] [saucenao] [google]
12212790

Help boys, highlighted line is problematic.
If you have different proof that there is no retraction from closed disk to circle without fundamental groups, I would appreciate it.

>> No.12212810

>>12208548
Tutorial on how not to prove anything in your life.

>> No.12212821

>>12212371
Glorified hole counting.

>> No.12212825

>>12212821
Gloryhole counting?

>> No.12212840

>>12212825
You could use persistent homology to count the number of cocks visiting a gloryhole, sure.

>> No.12212843

>>12212790
I have a proof with homology, but you're probably not interested.
Why would you try do this without algebraic topology?

>> No.12212857

>>12212843
I'm not into gloryholes. I know proof that uses fundamental group the fact that Z is fundamental group of circle.

>> No.12212869

>>12212857
The homology proof is basically the same proof. It works for disks of any dimension though.

>> No.12212899

>>12212869
I'm not interested in it right now, but do you have any book recommendations for algebraic topology?

>> No.12212918
File: 474 KB, 733x720, 1470674490987.png [View same] [iqdb] [saucenao] [google]
12212918

>>12212107
Nice that someone liked it.

>>12212899
Rotman.

>> No.12212921

>>12212899
I learnt through Hatcher, some people here hate that book though.
Ghrist's Applied Topology cover's it from a more computational perspective, I'm not sure how useful it is as a first introduction though.

>> No.12212935

Anyone got cool less known elementary problems whose solution does not require high machinery just ingenuity?

>> No.12212949
File: 171 KB, 2048x1152, skynews-sir-roger-penrose-maths_5120264[1].jpg [View same] [iqdb] [saucenao] [google]
12212949

>OMFG
>crackpot ideas are back on the meny boys!

Time is a flat circle motherfuckers.

>> No.12212951

>>12212949
Fuck off faggot. Penrose is not a crank, he's a respectable mathematical physicist.

>> No.12212953

>>12212935
https://arxiv.org/pdf/1110.1556.pdf
Has some cool problems that were made to have elementary solutions.

>> No.12212957

>>12212951
I know but he's becoming more based with every year that passes. None of that boring ebony hole bs.

>> No.12213000

>>12212957
Oh, I thought you were mocking him. Yeah, he's pretty based.

>> No.12213025

https://en.wikipedia.org/wiki/Replication_crisis
Have you ever read a bullshit paper in math? Besides clowns like terrence howard.

>> No.12213032

>>12213025
>Have you ever read a bullshit paper in math?
I know Tooker has.

>> No.12213068

>>12213025
You ever get crazy emails from that guy?

>> No.12213078

>>12212953
Is problem 5 as easy as I think it is?

>> No.12213101

>>12213078
No, it's definitely harder thank you think it is.

>> No.12213128
File: 39 KB, 590x310, firefox_7jKpcnbXQb.png [View same] [iqdb] [saucenao] [google]
12213128

>>12213101
all done.

>> No.12213138

>>12213101
Yeah, I looked up the answer and it's very complicated.
But I still found the correct values of x without bothering to "think" or do "math."

>> No.12213142

>>12213078
It's pretty easy to find solutions. Have you shown that there are no other solutions than obvious ones?

>> No.12213143

>>12213101
This is also a good rule of thumb when doing maths

>> No.12213153

Will I be able to manage a math postgrad as a CS grad?

>> No.12213158

>>12213153
probably, depending on how much theoretical stuff you did.

>> No.12213160

>>12213153
What are you mathing in? What mathing did you do before?

>> No.12213172

>>12213160
Was thinking of doing a masters in pure and applied math, had 1 discrete math, 1 analysis, 4 calculus and 3 linear algebra courses

>> No.12213194

>>12213172
uhhhhh, good luck. If this is a canadian masters, you're gonna be a little (a lot) fucked

>> No.12213415

>>12213194
>Canadian

>> No.12213421

I like combinatorics and functional analysis. What should I study?

>> No.12213441

>>12213421
Graph theory

>> No.12213467

>be in proofs class
>girl (female) is presenting a proof
>her proof is incomplete
>some guy asks what if (case she didn't consider)?
>"I don't think that's possible"
I almost punched my screen, like nigga you have to prove that it's not possible that's the whole point of the course. Everybody chimes in to convince her that you don't necessarily know that that's not the case unless you prove it. Eventually she finally said "oops brain did a thing" or some shit like that and we moved on

>> No.12213477

>>12213441
idk the graph theory that I've done so far has had absolutely no analysis. Anything else?

>> No.12213683

>>12213467
Shit story.
Everyone has brain farts like this where they discount something nontrivial. If you don't ever accidentally do this then you're probably spending too long not discounting trivialities.

>> No.12213912
File: 56 KB, 750x737, 1601658254016.jpg [View same] [iqdb] [saucenao] [google]
12213912

>>12213683
Guess where you need to return to? It's not monke or atlantis. You arent invited there.

>> No.12214125

New >>12214123

>> No.12214318
File: 133 KB, 750x780, milk.jpg [View same] [iqdb] [saucenao] [google]
12214318

>>12213912
A bloo bloo bloo

>> No.12214600

>>12212524
yes

>> No.12215183

>>12211046
make a free body diagram

>> No.12215188

Should I learn multilinear algebra and differential forms?

>> No.12215313

>>12215188
Yes.