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Math-age: Japanese mathematician claims proof of abc conjecture

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XiaNaphryz

LATIN, MATRIPEDICABUS, DO YOU SPEAK IT
http://www.nature.com/news/proof-claimed-for-deep-connection-between-primes-1.11378

Proof claimed for deep connection between primes
If it is true, a solution to the abc conjecture about whole numbers would be an ‘astounding’ achievement.


Philip Ball
10 September 2012

The usually quiet world of mathematics is abuzz with a claim that one of the most important problems in number theory has been solved.

Mathematician Shinichi Mochizuki of Kyoto University in Japan has released a 500-page proof of the abc conjecture, which proposes a relationship between whole numbers — a 'Diophantine' problem.


The abc conjecture, proposed independently by David Masser and Joseph Oesterle in 1985, might not be as familiar to the wider world as Fermat’s Last Theorem, but in some ways it is more significant. “The abc conjecture, if proved true, at one stroke solves many famous Diophantine problems, including Fermat's Last Theorem,” says Dorian Goldfeld, a mathematician at Columbia University in New York. “If Mochizuki’s proof is correct, it will be one of the most astounding achievements of mathematics of the twenty-first century.”

Like Fermat’s theorem, the abc conjecture refers to equations of the form a+b=c. It involves the concept of a square-free number: one that cannot be divided by the square of any number. Fifteen and 17 are square free-numbers, but 16 and 18 — being divisible by 4^2 and 3^2, respectively — are not.

The 'square-free' part of a number n, sqp(n), is the largest square-free number that can be formed by multiplying the factors of n that are prime numbers. For instance, sqp(18)=2×3=6.

If you’ve got that, then you should get the abc conjecture.
It concerns a property of the product of the three integers axbxc, or abc — or more specifically, of the square-free part of this product, which involves their distinct prime factors. It states that for integers a+b=c, the ratio of sqp(abc)^r/c always has some minimum value greater than zero for any value of r greater than 1. For example, if a=3 and b=125, so that c=128, then sqp(abc)=30 and sqp(abc)^2/c = 900/128. In this case, in which r=2, sqp(abc)^r/c is nearly always greater than 1, and always greater than zero.

Deep connection

It turns out that this conjecture encapsulates many other Diophantine problems, including Fermat’s Last Theorem (which states that a^n+b^n=c^n has no integer solutions if n>2). Like many Diophantine problems, it is all about the relationships between prime numbers. According to Brian Conrad of Stanford University in California, “it encodes a deep connection between the prime factors of a, b and a+b”.

Many mathematicians have expended a great deal of effort trying to prove the conjecture. In 2007, French mathematician Lucien Szpiro, whose work in 1978 led to the abc conjecture in the first place claimed to have a proof of it, but it was soon found to be flawed.

Like Szpiro, and also like British mathematician Andrew Wiles, who proved Fermat’s Last Theorem in 1994, Mochizuki has attacked the problem using the theory of elliptic curves — the smooth curves generated by algebraic relationships of the sort y^2=x^3+ax+b.

There, however, the relationship of Mochizuki’s work to previous efforts stops. He has developed techniques that very few other mathematicians fully understand and that invoke new mathematical ‘objects’ — abstract entities analogous to more familiar examples such as geometric objects, sets, permutations, topologies and matrices. “At this point, he is probably the only one that knows it all,” says Goldfeld.

Conrad says that the work “uses a huge number of insights that are going to take a long time to be digested by the community”. The proof is spread across four long papers, each of which rests on earlier long papers. “It can require a huge investment of time to understand a long and sophisticated proof, so the willingness by others to do this rests not only on the importance of the announcement but also on the track record of the authors,” Conrad explains.

Mochizuki’s track record certainly makes the effort worthwhile. “He has proved extremely deep theorems in the past, and is very thorough in his writing, so that provides a lot of confidence,” says Conrad. And he adds that the pay-off would be more than a matter of simply verifying the claim. “The exciting aspect is not just that the conjecture may have now been solved, but that the techniques and insights he must have had to introduce should be very powerful tools for solving future problems in number theory.”


Nature
doi:10.1038/nature.2012.11378

The several papers cited above that cover the proof:

Mochizuki, S. Inter-universal teichmuller theory I: construction of Hodge Theatres (2012). available at http://www.kurims.kyoto-u.ac.jp/~motizuki/Inter-universal Teichmuller Theory I.pdf
Mochizuki, S. Inter-universal teichmüller theory II: Hodge–Arajekekiv-theoretic evalulation (2012). available at http://www.kurims.kyoto-u.ac.jp/~motizuki/Inter-universal Teichmuller Theory II.pdf
Mochizuki, S. Interuniversal teichmüller theory III: canonical splittings of the log-theta-lattice (2012). available at http://www.kurims.kyoto-u.ac.jp/~motizuki/Inter-universal Teichmuller Theory III.pdf
Mochizuki, S. Interuniversal teichmüller theory IV: log-volume computations and set-theoretic foundations (2012). available at http://www.kurims.kyoto-u.ac.jp/~motizuki/Inter-universal Teichmuller Theory IV.pdf

And the mathematician's home page: http://www.kurims.kyoto-u.ac.jp/~motizuki/papers-english.html
 

Lonely1

Unconfirmed Member
The problem with this proofs is that they are so complicated that only a select few are able to verify them. Just like Wile's proof.

Not that I believe they are wrong, though, or that a less complex proof even exist :)
 

Tomat

Wanna hear a good joke? Waste your time helping me! LOL!
Doing simple proofs in Calculus that didn't even take up a page was already bad enough for me.

A 500 page proof scares the hell out of me. That much work is absolutely staggering and commendable.
 

JavaMava

Member
So what are the consequences in real life?

Triangles as we know it will never be the same. Keep this next part under your hat though.... word on the street is this may effect a couple rectangles as well. If I were you I'd put all my money into circles. You just never know.
 

Won

Member
I was always wondering what mathematicians do the whole day. Now that's a mystery solved.

Oh and that abc thing too, I guess.
 

Tesseract

Banned
i5UdJkusIWsLH.gif
 

wolfmat

Confirmed Asshole
So what are the consequences in real life?

It's not always possible to immediately see applications in engineering, experimental physics, whatever else, that follow from proofs in math. But that doesn't mean they don't exist at all. That's all I got. This stuff is wayyy over my head, of course.
 

Omikaru

Member
this sounds like theoretical wankery with no practical application but maybe I'm wrong.

Personally, I find knowledge for knowledge's sake (or discovery for discovery's sake!) has more value than posting a snarky comment on NeoGAF, but maybe I'm wrong.

I'm sure for some people this is very interesting and intellectually stimulating. Who cares if it doesn't have a practical application?

Honestly, I don't know if this ever will or not. Maybe one day the solution will be useful for someone. Who knows? Just because we can't immediately see what said solution will lead to, or even if there's no practical motive behind solving it in the first place, it doesn't mean to say that it's "wankery" or not worth knowing.
 

ronito

Member
Dude that's like the 3rd time you've posted that image. Is this your rememberance of 9/11 or something?

can someone explain this to me in layman's terms
Right now the only way to know a number is prime is try and divide it by everything.
Now with this it could be technically possible to create a formula to figure out primes and to do that for very large numbers. Instead of going and having to divide it by everything.

Essentially, it's an esoteric problem that someone possibly solved. Real world implications, some things might get faster.
 

Mondriaan

Member
It turns out that this conjecture encapsulates many other Diophantine problems, including Fermat’s Last Theorem (which states that an+bn=cn has no integer solutions if n>2). Like many Diophantine problems, it is all about the relationships between prime numbers. According to Brian Conrad of Stanford University in California, “it encodes a deep connection between the prime factors of a, b and a+b”.
I know that this is a copy/paste, but I think you should have modified the text to say something more like a^n + b^n = c^n since we don't have superscript.
 
Dude that's like the 3rd time you've posted that image. Is this your rememberance of 9/11 or something?


Right now the only way to know a number is prime is try and divide it by everything.
Now with this it could be technically possible to create a formula to figure out primes and to do that for very large numbers. Instead of going and having to divide it by everything.

Essentially, it's an esoteric problem that someone possibly solved. Real world implications, some things might get faster.

Could it not also obsolete a large class of encryption techniques?

Edit: I can't wrap my head around what a square free number is, mainly because of this part.

Like Fermat’s theorem, the abc conjecture refers to equations of the form a+b=c. It involves the concept of a square-free number: one that cannot be divided by the square of any number. Fifteen and 17 are square free-numbers, but 16 and 18 — being divisible by 42 and 32, respectively — are not.

16 is divisible by 42? huh? 18 is divisible by 32?

Fake Double edit. Wait, I think the 2's are not supposed to be there. 16 is divisible by 4 which is a square number, and 18 is divisible by 9, which is 3^2. Perhaps a better summation of a square free number is a number whose prime factorization does not contain the same prime number twice.

Triple edit: yep, it was a copypasta error reading the original article.
 

PGamer

fucking juniors
and yours is a terribly useless one. If you have some arcane knowledge about this that the rest of us don't then please, share.
I'd like to share a quote by John von Neumann, one of the greatest mathematicians of the 20th century:

"A large part of mathematics which becomes useful developed with absolutely no desire to be useful, and in a situation where nobody could possibly know in what area it would become useful; and there were no general indications that it ever would be so. By and large it is uniformly true in mathematics that there is a time lapse between a mathematical discovery and the moment when it is useful; and that this lapse of time can be anything from 30 to 100 years, in some cases even more; and that the whole system seems to function without any direction, without any reference to usefulness, and without any desire to do things which are useful."

Mathematics is quite often developed well before any practical use is known. The field of number theory, of which this problem is from, was thought to be completely useless in the real world for a long time. That is until people realized it had major implications in cryptography, which has done things such as help break Nazi codes in World War II to powering encrypted internet communications today. Stating that a new advancement in mathematics is "theoretical wankery with no practical application" is only really showing how very clueless about the subject you are.
 
Seeing threads like this really gets me down because I was very much not into mathematics, and it's carried over into college; my major had minimal math requirements, which on one hand I am happy about (the stress of math, for me, is crippling sometimes). On the other hand I would have loved to be someone that "gets" the advanced mathematics as they seem fascinating.

Good on you, math folk.
 
Seeing threads like this really gets me down because I was very much not into mathematics, and it's carried over into college; my major had minimal math requirements, which on one hand I am happy about (the stress of math, for me, is crippling sometimes). On the other hand I would have loved to be someone that "gets" the advanced mathematics as they seem fascinating.

Good on you, math folk.


As someone who is in precalculus, I can confirm your suspicions that being able to count oneself among the "mathematical elite" is indeed awesome.
 

poppabk

Cheeks Spread for Digital Only Future
this sounds like theoretical wankery with no practical application but maybe I'm wrong.
Are you basing this on your understanding of the papers or your lack of understanding?
I am sure that fourier transforms seemed like theoretical wankery when they were first discovered in the 18th century, but in the computer age the mathematics is very useful.
And it's not just the outcome but the tools he developed to get there.
 

Randdalf

Member
Seeing threads like this really gets me down because I was very much not into mathematics, and it's carried over into college; my major had minimal math requirements, which on one hand I am happy about (the stress of math, for me, is crippling sometimes). On the other hand I would have loved to be someone that "gets" the advanced mathematics as they seem fascinating.

Good on you, math folk.

I'm kind of the opposite, I cruised through maths all the way until university and I just found the rigor and precision both frustrating, confusing and not much fun at all. So I switched my course to Computer Science which is much more enjoyable to learn.

I respect scientists and mathematicians, but I know at some point I just can't comprehend that stuff.

Like with Andrew Wiles's proof of Fermat's Last Theorem, I expect there are very few people in the world who have the knowledge to understand this paper.
 

Axalon

Member
Wait... how?

Nearly all encryption techniques are built on the fact that factoring products of large prime numbers are difficult. Like, it would take longer than the universe has currently existed long, given enough digits, whereas multiplying the primes to generate said number would take about a minute or so. If we can factor large numbers quickly, well, all that stuff you thought was private is, well, no longer private. You'd be able to crack codes in milliseconds. The fact that there's no quick way to factor large numbers (of which ones made by large prime numbers are exceptionally difficult) is what keeps current encryption algorithms working.

See http://en.wikipedia.org/wiki/Integer_factorization
 

Brazil

Living in the shadow of Amaz
Nearly all encryption techniques are built on the fact that calculating large prime numbers are difficult. Like, it would take longer than the universe has currently existed long, given enough digits (about 60 should do it). If we can calculate prime numbers quickly, well, all that stuff you thought was private is, well, no longer private. You'd be able to crack codes in milliseconds.

Well, dang.
 

B-Dubs

No Scrubs
On paper it could.
If someone could simplify it in an easy way then technically yes but then you'd figure they'd use it to make encryption far larger too.

Pretty much, if someone can simplify this then it's going to be a big deal for computer safety.
 
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