[HN Gopher] After 20 years, math couple solves major group theor...
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       After 20 years, math couple solves major group theory problem
        
       Author : isaacfrond
       Score  : 355 points
       Date   : 2025-02-20 10:09 UTC (12 hours ago)
        
 (HTM) web link (www.quantamagazine.org)
 (TXT) w3m dump (www.quantamagazine.org)
        
       | thih9 wrote:
       | This is about McKay conjecture
       | 
       | https://en.m.wikipedia.org/wiki/McKay_conjecture
        
         | alberto_ol wrote:
         | Non mobile link
         | 
         | https://en.wikipedia.org/wiki/McKay_conjecture
        
       | ChrisMarshallNY wrote:
       | Damn. That's some dedication. I really like the personal story,
       | therein. You don't always see that, in STEM stuff.
       | 
       | I hope that their relationship deals well with the new reality,
       | now that their principal goal has been achieved.
        
         | nthingtohide wrote:
         | I think experts in all kinds of fields should write more about
         | their thinking process. Just showing final result often feels
         | like it was easy for them and discourages other from even
         | attempting to understand and contribute. Especially in
         | mathematics, the ideas are simple (they have to be because no
         | one would be summing infinite series in their head like
         | Ramanujan) but they are hidden behind lot of symbolic jargons.
        
           | grandempire wrote:
           | It's always less impressive to know how it works and fewer
           | people care.
        
             | nthingtohide wrote:
             | Here's an example of what I meant
             | 
             | Lecture by Douglas Hofstadter: Albert Einstein on Light;
             | Light on Albert Einstein
             | 
             | https://youtu.be/ePA1zq56J1I?si=7WuiRa3GNSmMXArZ
        
       | lo_fye wrote:
       | Way to go, Math!
        
       | socceroos wrote:
       | What a mathive achievement!
        
       | yamrzou wrote:
       | "While working together on the McKay conjecture, Britta Spath and
       | Marc Cabanes fell in love and started a family."
        
         | Out_of_Characte wrote:
         | They found their succession
        
           | anthk wrote:
           | Intersection set with genes from set A and B.
        
             | inglor_cz wrote:
             | With the kids being homeomorphic to the parents.
        
             | echoangle wrote:
             | Wouldn't it be more like a subset of the union of A and B?
             | Intersection set sounds like the child only has the genes
             | that both parents share.
        
               | anthk wrote:
               | True; that would be dangerously close to incest. Subset
               | of a union, then.
        
               | veidr wrote:
               | FFS you nerds, get a room
               | 
               | (and then form a working group to devise an algebraically
               | provable disincentive to incestuous calculation)
        
               | Out_of_Characte wrote:
               | Way ahead of you, pal. I am my own grandpa.
               | 
               | https://youtu.be/eYlJH81dSiw?si=NNPDjaWV-OzrP2JU
        
           | thaumasiotes wrote:
           | https://www.youtube.com/watch?v=BipvGD-LCjU
        
       | charlangas wrote:
       | How do these kinds of advancements in math happen? Is it a
       | momentary spark of insight after thinking deeply about the
       | problem for 20 years? Or is it more like brute forcing your way
       | to a solution by trying everything?
        
         | getnormality wrote:
         | In this case, a ton of progress had already been made. The
         | conjecture had been proved in some cases, reduced to a simpler
         | problem in others. This couple went the last mile of solving
         | the simpler problem in some particularly thorny cases.
         | 
         | You're really standing on the shoulders of giants when you rely
         | on the classification of finite simple groups.
        
           | btilly wrote:
           | _You 're really standing on the shoulders of giants when you
           | rely on the classification of finite simple groups._
           | 
           | Giants whose work has (dirty little secret) never truly been
           | verified. The proof totals about 10,000 pages. At the end of
           | the effort to prove it there were lots of very long papers,
           | with a shrinking pool of experts reviewing them. There have
           | been efforts to reprove it with a more easily verified proof,
           | but they've gone nowhere.
           | 
           | Hopefully, the growing ease of formalization will lead to a
           | verification some day. But even optimistically that is still
           | a few years out.
        
             | isotypic wrote:
             | > There have been efforts to reprove it with a more easily
             | verified proof, but they've gone nowhere.
             | 
             | My understanding was that the so called "second generation
             | proof" of the classification of finite simple groups led by
             | Gorenstein, Lyons, Solomon has been progressing slowly but
             | steadily, and only the quasithin case had a significant
             | (but now fixed) hole. Are there other significant gaps that
             | aren't as well known?
        
               | btilly wrote:
               | Huh. Looking at it, they have made a lot more progress
               | than I was aware of. I will correct my opinion.
               | https://mathoverflow.net/questions/114943/where-are-the-
               | seco... was very informative on this.
               | 
               | Still they have a couple more books of proof left, and I
               | have to wonder how carefully it will be reviewed. This
               | will still be a massive improvement, but I'd be a lot
               | happier if the entire proof could be formalized.
               | 
               | Plus there is still a possibility that there proves to be
               | another significant hole.
               | 
               | If any theorem needs to be formalized, this is the one.
               | No other theorem is this big, this hard to prove, and
               | this important to get right.
        
               | getnormality wrote:
               | At the moment we seem to have exactly one guy equipped to
               | do this, and he'll be busy with something else for the
               | next few years: https://www.reddit.com/r/math/comments/17
               | 6vtju/kevin_buzzard...
        
         | jebarker wrote:
         | My experience from proving a moderately complicated result in
         | my PhD was that it's neither. There wasn't enough time to brute
         | force by trying many complete solutions, but it also wasn't a
         | single flash of insight. It was more a case of following a path
         | towards the solution based on intuition and then trying a few
         | different approaches when getting stuck to keep making
         | progress. Sometimes that involves backtracking when you realize
         | you took a wrong path.
        
           | sweezyjeezy wrote:
           | Yeah agreed - there are actually many, smaller flashes of
           | insight, but most of them don't lead to anything. I once
           | joked that you could probably compress all the time I was
           | actually going in the right direction in my PhD down to about
           | a month or two. That's a bit glib, often seeing why an
           | approach fails gives you a much better idea of what a proof
           | 'has to look like' or 'has to be able to overcome'. But many
           | months of my PhD were working on complete dead-ends, and I
           | certainly had a few very dark days because of that. Research
           | math takes a lot of perseverance.
        
             | jebarker wrote:
             | > Research math takes a lot of perseverance.
             | 
             | Yup, I think stubbornness/perseverance is the most useful
             | transferrable skill I got from doing research math. It's a
             | double-edged sword though as I often just can't give up
             | working on something when I really should in my tech job.
        
         | bloomingkales wrote:
         | The structure of DNA was seen in a vision in James Watson's
         | dream. Some say it's subconscious problem solving and I think
         | most down to earth people agree with that, but some less down
         | to earth people will absolutely attribute it to god (I'm in the
         | latter). If we were to entertain a silly proposition, something
         | in the universe could just move our story along, all of a
         | sudden. These paradigm shifts just seem to appear.
        
           | FartyMcFarter wrote:
           | Subconscious problem solving is definitely a thing as far as
           | I'm concerned.
           | 
           | It's happened several times that I struggled with a bug for
           | hours, then suddenly came up with a key insight during the
           | commute home (or while taking a shower or whatnot), while not
           | actively thinking about the problem. I can't explain this any
           | other way than some kind of subconscious "brainstorming"
           | taking place.
           | 
           | As a side note, this doesn't mean the hours of conciously
           | struggling with the problem were a waste. I bet that this
           | period of focus on the problem is what allows for the later
           | insights to happen. Whether it's data gathering that alows
           | the insights to happen, or even just giving importance to the
           | problem by focusing on it. Most likely it's both.
        
             | fsckboy wrote:
             | an alternate hypothesis is that all thinking is unconscious
             | with consciousness being the sum of many unconscious
             | processes. So, while it's true as you say "that some kind
             | of subconscious "brainstorming" taking place", that would
             | just true all the time, and you only notice it when your
             | conscious thoughts are of something else.
             | 
             | (n.b. historically speaking in the literature,
             | "subconscious" was the word used to describe Jung's "woo-
             | woo" ideas about a collective subconscious shared across
             | populations, and unconscious was the word used for ideas
             | about a single brain a la Freud which is what we are
             | talking about here)
        
           | y33t wrote:
           | > The structure of DNA was seen in a vision in James Watson's
           | dream
           | 
           | I believe this is apocryphal. Watson likely said this because
           | he stole Rosalind Franklin's research.
        
             | bloomingkales wrote:
             | I can only think of that example because it's the only one
             | I know of where the scientist admitted to something divine.
             | 
             | This is probably something I need to research more, because
             | the questions scientists are dealing with are too deep to
             | ignore the one big question, and I wonder who struggled
             | with it.
        
               | selimthegrim wrote:
               | Kekule?
        
               | Philpax wrote:
               | Ramanujan is another great example of divine inspiration.
        
               | hcs wrote:
               | Not divine specifically but I like the Wikipedia List of
               | Dreams: https://en.wikipedia.org/wiki/List_of_works_based
               | _on_dreams#...
        
             | btilly wrote:
             | I disagree. What he stole was the pictures she took. He
             | really did come up with the structure.
             | 
             | Mind you he was helped by a nice coincidence. Franklin knew
             | all 230 space symmetry groups, and so had to sort through
             | them. Watson only really knew one - his PhD thesis was on a
             | protein with the same group as DNA.
        
       | Jun8 wrote:
       | Hah, serendipity: I was reading the Groups part of the Infinite
       | Napkin after it was posted on HN recently. I understand the
       | definitions, etc. but still haven't grasped the central
       | importance of groups.
       | 
       | For example, article says there are 50 groups of order 72
       | (chatGPT says there are 50 non-Abelian, 5 Abelian), this seems to
       | be an important insight but into what?
        
         | Chinjut wrote:
         | Don't listen to ChatGPT. There are 44 non-abelian and 6 abelian
         | groups of order 72. I wouldn't say these particular numbers are
         | terribly important, but they are correct.
        
           | Imustaskforhelp wrote:
           | Don't listen to ChatGPT.
           | 
           | As someone "junior programmer" , I think I should just keep
           | this information . Many times I have tried to not use
           | chatgpt. but its just so lucrative.
           | 
           | I really need better control of myself. Going to block
           | chatgpt at a dns level.
        
           | jandrese wrote:
           | Definitely don't use ChatGPT to try to learn about something
           | you have no knowledge of. It's impossible to separate the
           | bullshit from the truth if you don't already have some
           | foundation in the field, and chatbots often try to sneak some
           | bullshit in there.
        
         | grandempire wrote:
         | Many mathematical structures are groups so understanding them
         | helps you get insight into the concrete situation you are
         | trying to solve. For example is the problem I am seeing
         | abelian? If so then it must look like X or Y.
        
         | __MatrixMan__ wrote:
         | I've only taken three (undergrad) classes involving groups so
         | I'm far from an expert but my feeling is that their underlying
         | structure is a bit like prime numbers.
         | 
         | Nobody bothers explaining why the primes are spaced like they
         | are, rather people explain other phenomena by pointing out that
         | certain things about it are prime or not.
         | 
         | For instance, there's this thing about having a nice neat
         | formula for factoring second degree polynomials (the quadratic
         | formula). One also exists for cubics and quartics (though they
         | don't usually have you memorize these) but none exists for
         | quintics. It took mathematicians a while to prove that such a
         | thing doesn't exist (how to prove a negative?) but they managed
         | it by arguing that all such things have an underlying finite
         | group smaller than a certain size and look, we've listed them
         | here, and there's no such group corresponding to a quintic
         | formula, therefore there is no quintic formula.
         | 
         | So they're useful as a sort of primordial complexity that can
         | be referenced without extensive explanation since properties
         | about the small ones can be checked by hand. And as it turns
         | out, quite a lot of things form groups if you bother you look
         | at them that way.
        
           | BlackFingolfin wrote:
           | > Nobody bothers explaining why the primes are spaced like
           | they are
           | 
           | I take it that means you also haven't taken (m)any number
           | theory classes then ;-). Because people _wildly_ care about
           | that.
           | 
           | This is in a sense the background of another well-known
           | conjecture, the Riemann conjecture...
        
             | __MatrixMan__ wrote:
             | Fair point, and correct (just one class). Myself, I'm fine
             | with a field being important because well it's a mystery of
             | the universe and well we just couldn't not scratch the
             | itch. But I know that not all askers want answers like
             | that, so I was attempting to dust off the "it's also
             | useful" neurons :)
        
         | ndriscoll wrote:
         | Groups are important because they are the algebraic way to
         | describe symmetry: if you have some operation that leaves a
         | thing invariant (e.g. rotating an equilateral triangle so that
         | a vertex lands on where another started), then the operation is
         | invertible and the inverse leaves the thing invariant. You can
         | compose such operations and the composition will still be
         | invariant. The identity function always leaves everything
         | invariant. So your symmetry operations form a group.
         | 
         | Slightly trickier is that every group is a set of symmetry
         | operations for something. So groups _exactly_ capture the idea
         | of symmetry. To a mathematician,  "group" and "symmetries" are
         | synonymous.
         | 
         | Finite groups can be interesting as the symmetries of e.g.
         | molecules (e.g. rotating atoms around onto each other), which
         | can tell you something about molecular structure, energy
         | levels, spectra, bonding potential, etc. Infinite groups appear
         | in physics (e.g. the laws of physics are the same when you
         | rotate or translate your coordinates by arbitrary amounts).
         | Symmetry also comes up as a way to study other mathematical
         | objects, and mathematicians might just want to know what all
         | possible groups look like.
        
       | w0de0 wrote:
       | With the right photo, this could be an Onion headline poking fun
       | at lonely math nerds.
        
       | PhillyPhuture wrote:
       | "There was a risk that such a single-minded pursuit of so
       | difficult a problem could hurt her academic career, but Spath
       | dedicated all her time to it anyway."
       | 
       | I feel like this sentence is in every article for a reason. Thank
       | goodness there are such obsessive people and here's a toast to
       | those counter-factuals that never get mentioned.
        
         | Der_Einzige wrote:
         | Unfortunately the average persons hatred of autistic or nerdy
         | people implies that many believe the world would be a better
         | place if "obsessive types" didn't exist.
         | 
         | Hans Asperger could only save his Austic children from nazi
         | death camps by convincing the nazis that they had value to
         | produce rockets and bombs.
         | 
         | It's quite remarkable that the USA is so advanced given how
         | deep and ruthless our anti-intellectualism goes.
        
           | veidr wrote:
           | Isn't it basically the same? Nazi Germany in 1934 was
           | relatively advanced, too.
           | 
           | I think the difference is^W was that USA celebrated it in a
           | Homer Simpson kind of "Ha ha! NERDS!" way, while meth-Hitler
           | was like "let's sterilize them but try to extract math from
           | them to... (whatever batshit goal)"
           | 
           | Anti-intellectualism seems to be a thing when the
           | intellectual/moderately-competent people have already brought
           | success. (Until then it's more like anti-witchcraft, or
           | whatever...)
        
           | Gud wrote:
           | I don't think the average person hate autistic or nerdy
           | people.
        
             | throwpoaster wrote:
             | Yes, they do. They wouldn't say it, but look at how
             | autistic people get treated by their peers, teachers, and
             | bosses.
        
               | jonnybgood wrote:
               | How do you know their peers, teachers, and bosses aren't
               | autistic too? Autistic people can't be peers, teachers,
               | and bosses? Autistic people can be assholes too. Maybe
               | that's what it really is: some people are just assholes.
        
               | yifanl wrote:
               | Extreme category error, try again.
        
             | parineum wrote:
             | They absolutely don't.
             | 
             | The average person is probably uncomfortable around
             | autistic people because they don't know how to deal with
             | them and, when you see someone like that, it's usually best
             | to avoid interacting with them. Not because autistic people
             | are dangerous but people acting out of the ordinary
             | sometimes are.
             | 
             | The lumping in of nerdy with autistic is ridiculous too.
             | The average person just doesn't care about your interests
             | unless they are in common. Nerdy typically just means
             | having a niche interest or hobby.
             | 
             | Your parent reeks of a persecution complex.
        
               | Der_Einzige wrote:
               | It's shocking that you can just bury your head in the
               | sand about the colloquial usage of "autist" (often
               | happening at the same time as "Incel") replacing "retard"
               | in the lexicon of the average zoomer.
               | 
               | It's not a persecution complex to identify the ways that
               | hate gets used, deployed, and repackaged for a new
               | generation. Putting your head in the sand about stuff
               | like this is why Trump winning the election was SO
               | shocking to some and extremely obvious to others.
        
               | mike_ivanov wrote:
               | I guess you never studied in a school and therefore not
               | aware of bullying and its stereotypical targets.
        
             | MattGrommes wrote:
             | Obviously everything is a spectrum but I agree. If
             | anything, "a touch of the 'tism" is the new "I have OCD"
             | because you like a clean desk, something people are fine
             | with saying without regards to it being true.
        
           | jonahx wrote:
           | "the average persons hatred of autistic or nerdy people"
           | 
           | This is a _wildly_ inaccurate picture of the average person.
           | I don 't even think this is true of 10% of people.
        
             | lanstin wrote:
             | Probably enough for 90% of such folks to be tormented quite
             | effectively during childhood.
        
               | bear141 wrote:
               | This is a great point. If a small percentage of the
               | population is openly and aggressively negative towards
               | another part of the population, it makes sense that they
               | would both artificially appear as if they are a larger
               | part of the population, to each other. I think it goes
               | both ways.
        
               | macbem wrote:
               | Anyone who's a bit different has a high chance of having
               | been bullied at some point. It doesn't mean that society
               | hates this specific group of people.
        
               | LPisGood wrote:
               | I _highly_ doubt 90% of nerdy people were tormented
               | during childhood. Have you spent time in/around academia?
               | These people are massive nerds and horrendous childhood
               | torment is pretty rare.
        
               | ted_dunning wrote:
               | It was 100% in my personal experience.
        
               | LPisGood wrote:
               | I'm not saying it doesn't happen. I'm not even saying it
               | doesn't happen at all higher rate than the general
               | population.
               | 
               | But 90% is just too much to be feasible.
        
             | MrMcCall wrote:
             | Our son was specifically chosen to be in his 4th Grade
             | class because it spent part of the day hosting the spectrum
             | kids within their "regular" class. He was chosen for that
             | honor because of his kindness.
             | 
             | He has been taught to love others since he was born, and
             | the Path of Love has borne fruit for all those around all
             | four of us.
             | 
             | All the people who say it can't be done have never tried
             | consciously evolving with Divine help.
             | 
             | {Complete lyrics} --Sinead O'Connor in Massive Attack's
             | "What Your Soul Sings"
        
           | tim333 wrote:
           | US intellectualism is patchy. Sure a lot of people are not
           | into it but on the other hand you probably have more well
           | paid academic posts than any other country.
        
           | manoweb wrote:
           | What are you talking about, why do you think that autistics
           | are treated better in Europe, Africa, Asia? Also, people do
           | not "hate" them, people in general hate everybody, don't play
           | the victim
        
           | BobaFloutist wrote:
           | Probably the most powerful man in the world right now openly
           | self-identifies as autistic. Obviously there are very many
           | autistic people who get treated very badly, but I don't think
           | it's reasonable to say that the average person "hates"
           | autistic people.
        
             | harrison_clarke wrote:
             | that guy is arguably causing branding problems for less
             | powerful autistic people
        
               | BobaFloutist wrote:
               | Yeah I wouldn't want to be an autistic person that
               | doesn't suck right now.
               | 
               | I imagine it's a lot like my experience of having ADHD
               | and being trapped between wanting leeway and support but
               | also wanting to be held accountable and considered
               | capable of improving and watching the Tiktokification of
               | my disorder force me to argue that actually people with
               | ADHD _can_ do things and no having it doesn 't fully
               | excuse you from ever meeting commitments or doing the
               | fucking dishes, especially if you're rejecting all and
               | any treatment or strategy.
        
         | manoweb wrote:
         | There are tens of millions of people doing a repetitive work
         | every day, instead of being entrepreneurs. Just let them be,
         | not everybody needs to dedicate their existence to maximizing
         | their career opportunities, at any level.
        
           | chowells wrote:
           | This isn't being an entrepreneur. This is solving a problem.
           | The two almost never overlap.
        
           | godelski wrote:
           | > Just let them be
           | 
           | As someone who's research goes against the grain, I just
           | request the same. I have no problem with people maintaining
           | the course and doing the same thing. In fact /most/ people
           | should probably be doing this. BUT the system discourages
           | going of course, exploring "out of bounds." The requests of
           | these people have always been "let me do my thing."
           | 
           | Just make sure "let them be" applies in both directions
        
         | tomcam wrote:
         | I worked at a pro audio company where one guy spent 5 years on
         | a power supply. It succeeded, and I always appreciated the
         | management for supporting him.
        
           | lemonberry wrote:
           | Do recall the specific problem he was trying to solve?
           | 
           | It's amazing to me how much thought and work has gone into
           | the seemingly trivial things we encounter on a daily basis.
           | 
           | I think of this every time I see a blue LED. Or a rice
           | cooker!! So easy to take for granted.
        
         | yujzgzc wrote:
         | And you can thank this guy for the LEDs that made it possible
         | for you to even read about it on a screen
         | https://youtu.be/AF8d72mA41M
        
         | Xcelerate wrote:
         | I want financial independence for the sole reason that I can
         | work on interesting problems like this without any outside
         | nagging or funding issues from anyone else (there might still
         | be some judgment, but I can ignore that).
         | 
         | Personally I think governments should fund more moonshot solo
         | or small team efforts because high risk / high reward pays off
         | when you reduce the variance by spreading it out over so many
         | people. But it looks like we're going headstrong the other
         | direction in terms of funding in the U.S. right now, so I'm not
         | optimistic.
        
           | godelski wrote:
           | > I want financial independence for the sole reason that I
           | can work on interesting problems like this without any
           | outside nagging or funding issues from anyone else
           | 
           | Ditto. This is literally the only desire I have to be
           | wealthy. It is not about having nice things, a nice house, or
           | any of that. It is about letting me do my own research.
        
             | jereees wrote:
             | I bet there's a good number of us. How do we make this a
             | reality? :)
        
               | drivebyhooting wrote:
               | Last decades? Work in ad tech. Now? Work on LLMs.
        
         | godelski wrote:
         | > I feel like this sentence is in every article for a reason.
         | 
         | Breakthroughs, BY DEFINITION, come from people going against
         | the grain. Breakthroughs are paradigm shifts. You don't shift
         | the paradigm by following the paradigm.
         | 
         | I think we do a lot of disservice by dismissing the role of the
         | dark horses. They are necessary. Like you suggest, there are
         | many that fail, probably most do. But considering the impact,
         | even just a small percentage succeeding warrants significant
         | encouragement. Yet we often act in reverse, we discourage going
         | against the grain. Often with reasons about fear of failure. In
         | research, most things fail. But the only real failure is the
         | ones you don't learn from (currently it is very hard to publish
         | negative results. Resulting it not even being attempted. The
         | system encourages "safe" research, which by its nature, can
         | only be incremental. Fine, we want this, but it's ironic
         | considering how many works get rejected due to "lack of
         | novelty")
        
           | globnomulous wrote:
           | > Breakthroughs, BY DEFINITION, come from people going
           | against the grain. Breakthroughs are paradigm shifts.
           | 
           | This is wrong. It's not inherent in the meaning of the word
           | "breakthrough" that a breakthrough can occur only when
           | someone has gone against the grain, and there are countless
           | breakthroughs that have not gone against the grain. See: the
           | four-minute mile; the Manhattan Project; the sequencing of
           | the human genome; the decipherment of Linear B; research into
           | protein folding. These breakthroughs have largely been the
           | result of being first to find the solution to the problem or
           | cross the theshold. That's it. That doesn't mean the people
           | who managed to do that were working against the grain.
           | 
           | > Yet we often act in reverse, we discourage going against
           | the grain. Often with reasons about fear of failure.
           | 
           | I don't know which "we" you're referring to, but just about
           | everybody would agree with the statement that it's good to
           | think creatively, experiment, and pursue either new lines of
           | inquiry or old lines in new ways, so, again, your claim seems
           | clearly wrong.
           | 
           | If you're discussing just scientific research, though, sure,
           | there are plenty of incentives that encourage labs and PIs to
           | make the safe choice rather than the bold or innovative
           | choice.
        
             | pinoy420 wrote:
             | Yea but this is HN where everyone is a disruptor and
             | doesn't play by the rules
        
           | MrMcCall wrote:
           | > Breakthroughs, BY DEFINITION, come from people going
           | against the grain.
           | 
           | They are what Gladwell calls, in "David and Goliath", being
           | _unreasonable_ in the face of so-called  "prevailing wisdom".
        
           | inetknght wrote:
           | > _Often with reasons about fear of failure._
           | 
           | If that were it, I would agree.
           | 
           | But I don't agree. I think people who discourage going
           | against the grain are more fearful of the loss of economic
           | input. It's unproductive to do something you _know_ will
           | fail; it 's very expensive to encourage that failure.
        
       | isaacfrond wrote:
       | So what the McKay conjecture is saying is this.
       | 
       | Suppose I'm interested in representing a Group as matrices over
       | the complex numbers. There are usually many ways of doing this.
       | Each one of them has a so-called character, which is like
       | fingerprint of such a representation.
       | 
       | Along another line, it has been known that all groups contain
       | large subgroup having an order which is a power of a prime--call
       | it P. This group in turn has a normalizer in which P is normal--
       | call it N(P).
       | 
       | The surprising thing is that the number of characters of G and of
       | N(P)--which is is only a small part of G--is equal.
       | 
       | *technical note in both cases we exclude representation the
       | degree of which is a multiple of p.
        
         | antonf wrote:
         | Did you miss definition of G, or I didn't have enough caffeine
         | yet?
        
           | throwpoaster wrote:
           | I assume from context it's the original group, but I'm only a
           | cup deep.
        
             | looofooo0 wrote:
             | Correct
        
       | jmount wrote:
       | > When the couple announced their result, their colleagues were
       | in awe. "I wanted there to be parades," said Persi Diaconis
       | (opens a new tab) of Stanford University. "Years of hard, hard,
       | hard work, and she did it, they did it."
       | 
       | That sort of positive support was one of the elements I really
       | liked in working on combinatorial problems. People like Persi
       | Diaconis and D.J.A. Welsh were so nice it makes the whole field
       | seem more inviting.
        
         | MrMcCall wrote:
         | All our acts are butterfly wing beats that influence those with
         | whom we interact, for either good or ill. And those waves
         | resonate back within our being as happiness or its opposite,
         | depending on our intentions and actions.
         | 
         | "Positive vibration, yeah." --Bob Marley
        
       | xenago wrote:
       | What an awful webpage. They hijack the click and right click
       | actions. Can't triple click to select a paragraph. Can't drag
       | selected text. Ugh
        
         | PunchTunnel wrote:
         | What browser are you working in? I'm not having any trouble in
         | Brave, Chrome, or Opera.
        
           | xenago wrote:
           | Edge and Firefox both replicate the issue. It is on all
           | browsers
        
         | Imustaskforhelp wrote:
         | on zen , it works
        
       | justinpombrio wrote:
       | The paper: https://arxiv.org/abs/2410.20392
        
       | rurban wrote:
       | Their proof: https://arxiv.org/abs/2410.20392 (2024)
        
       | wglb wrote:
       | This is a terrific article. It led me to a couple of hours
       | tracking articles about related efforts, not the least of which
       | was John Conway's work.
       | 
       | Mind you, my math is enough for BSEE. I do have a copy of one of
       | my university professor's go-to work books: The Algebraic
       | Eigenvalue Problem and consult it occasionally and briefly.
        
       | racl101 wrote:
       | The couple that maths together stays together.
        
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