Zeta function in terms of Gamma function and Bose integral

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  • čas přidán 5. 09. 2024
  • Zeta function and Gamma functions,
    Bose Integral,
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Komentáře • 237

  • @GurkiratSingh-ds8dq
    @GurkiratSingh-ds8dq Před 6 lety +241

    Hey!, That's the Bose integral right? (Or something with a similar name)
    It comes up in Statistical mechanics quite some times.
    Nice!!!

    • @blackpenredpen
      @blackpenredpen  Před 6 lety +44

      Yes it is!!!

    • @GurkiratSingh-ds8dq
      @GurkiratSingh-ds8dq Před 6 lety +40

      blackpenredpen Wait, did you just change the title of the video or did I just not notice it before?

    • @blackpenredpen
      @blackpenredpen  Před 6 lety +67

      Gurkirat Singh
      I just changed the title. Since you reminded me.

    • @blackpenredpen
      @blackpenredpen  Před 6 lety +52

      Gurkirat Singh as a thank you. I will also pin your comment now!! Thank you!

    • @GurkiratSingh-ds8dq
      @GurkiratSingh-ds8dq Před 6 lety +37

      blackpenredpen I feel honoured. Thanks
      Btw since I am talking to you, One thing I never understood, why is the gamma function defined the way it is, I mean why couldn't they just define it to be the same as the factorial (for positive integers), and that -1 in the integral always seems a bit weird.
      I know that there's a PI function which fits my purposes, but Gamma is so much more in use. Why would the early mathematicians (who loved it's elegance) choose to define it as such?
      It will probably have some physics or application related reason, but nevertheless, it is worth asking

  • @duncanw9901
    @duncanw9901 Před 6 lety +268

    I feel like there should be a line in a horror movie where the antagonist slowly says "we are in the u world now."

  • @c8adec
    @c8adec Před 6 lety +72

    This is very useful in the Stefan-Bolzmann's law (black body irradiance) to get the sigma constant

    • @sinamehdizadeh1433
      @sinamehdizadeh1433 Před 4 lety +7

      Well, for everything related to blackbody radiation you need this.
      For example, the number density of photons is given by this integral too.

    • @integrando1847
      @integrando1847 Před 3 lety +3

      incredible application

    • @atrumluminarium
      @atrumluminarium Před 2 lety +1

      Also the Sommerfeld expansion

  • @frank95xxx
    @frank95xxx Před 2 lety +15

    I'm a physicist and I find this kind of integral quite often. We always say "some mathematician proved this result" but I never actually checked it. Nice to see the proof, good job BPRP

    • @createyourownfuture5410
      @createyourownfuture5410 Před 2 lety

      I had a question:
      Is it legal to use n first as a variable and then take the sum? It feels very sketchy.

  • @OonHan
    @OonHan Před 6 lety +189

    t = nu then tt = nut

  • @leonardromano1491
    @leonardromano1491 Před 6 lety +26

    This boi is a really nice one as it appears everywhere in quantum statistics in cases where the fugacity is equal to one.

  • @turtlellamacow
    @turtlellamacow Před 6 lety +8

    wow! i've seen integrals like your example near the end in statistical mechanics and elsewhere and never knew how they were evaluated. the textbook just gave us the value.

  • @frederickm9823
    @frederickm9823 Před 6 lety +39

    Finally I'm able to correct you. At 4:24 you say "x to the nth power" :D
    But it's still a great video =)

  • @rylanbuck1332
    @rylanbuck1332 Před rokem +1

    This was a question on my final exam of intro to real analysis (maa 5055) and I used this technique!!! I got stuck on proving the integral at 5:20 is uniformly convergent so I was unable to continue forward after that step:( but I’m glad to know I was doing the right thing lol

  • @mathiasfeijtel2449
    @mathiasfeijtel2449 Před 4 lety +2

    This is equivalent to showing that the Mellin transform of the function 1/(e^x -1) is the product of the Gamma function with the Riemann zeta function

  • @berenjervin
    @berenjervin Před 6 lety +5

    Sure wish these videos were around when I did my degree!
    These are great!

  • @kilogods
    @kilogods Před 6 lety +7

    This is like the first or second page of Riemann’s paper on primes.

  • @davidgillies620
    @davidgillies620 Před 4 lety +2

    You might also see this expressed as the product of the gamma function and the polylogarithm function Li_s(1) (which is zeta(s)). Polylogs crop up in related things like integral of x over exp(x) - 1

  • @lorenzodigiacomo2561
    @lorenzodigiacomo2561 Před 5 lety +1

    I think i asked for this integral time ago, while i was studying statistical mechanics, but i only saw the video today! great!

  • @cakes43
    @cakes43 Před 6 lety +3

    I recall seeing this result in my statistical physics course when we dealt with bose-einstein distribution. I never saw how this mathematical derivation, though. :) Awesome vid!!!

  • @kevincaotong
    @kevincaotong Před 6 lety +3

    I'm not sure if this is true, but I think I've heard from somewhere that Fubini's Theorem (or Tonelli's) only works when the function is continuous in the given interval. But then, I don't think we could integrate something that's not continuous in a given interval (unless we break it up into continuous intervals).
    But very interesting video! 😯 I bet the next video is "Proof of Riemann's Hypothesis".

  • @andrewandrus3296
    @andrewandrus3296 Před 4 lety +2

    that outro music had a Scott Joplin vibe, v-much appreesh

  • @AngeloYeo
    @AngeloYeo Před 6 lety +3

    oh... 我只在乎你 nice choice for an ending song ! :) Thanks for the uploading !

  • @dezkelz
    @dezkelz Před 6 lety

    Man, this is very cool. As a recent ME grad, I've been out of the calc3 maths world for a little while, but this makes me want to jump right back into it.

    • @Jeff-wc5ho
      @Jeff-wc5ho Před 6 lety

      Dean Congrats! :) also, out of curiosity, how much math were you required to take as an ME major?

    • @dezkelz
      @dezkelz Před 6 lety

      Thanks Jeff. After doing my calc series, I also had to take a linear algebra and an ODE differential equations course.

  • @Risu0chan
    @Risu0chan Před 6 lety

    and if you replace the zeta function by the alternate eta function, you change the sign in the denominator in the integral, from e^u - 1 to e^u + 1.

  • @ramez2775
    @ramez2775 Před 6 lety +1

    390 likes and 0 dislikes... that’s the most likes I’ve ever seen on a video with 0 dislikes. Keep up the good work! (:

  • @eduardkugler896
    @eduardkugler896 Před 3 lety

    If you read Planck Vorlesungen you find 1+1/2^4+1/3^4...=Zeta(4) for Stefan Boltzmann Integral. You can Take any Zeta of even Numbers of zeta, If you adapt the prefactor.

  • @AndDiracisHisProphet
    @AndDiracisHisProphet Před 6 lety +11

    I think for a counterexample where the exchange of sum and int doesn't work you have to come up with some really stupid functions like f_n= a_n*x from 0 to 1/n with a_n so that f_n(1/n)=1 or something like that

    • @marcioamaral7511
      @marcioamaral7511 Před 6 lety +5

      AndDiracisHisProphet Excuse me man
      I can see you've got a great understanding of maths and physics
      Never thought of making some vids? (I would love to see them)

    • @AndDiracisHisProphet
      @AndDiracisHisProphet Před 6 lety +9

      How do you know I have understanding of math and physics?
      Also, I would probably make them in german^^
      Also, I am ugly af. You wouldn't want to see me :D

    • @marcioamaral7511
      @marcioamaral7511 Před 6 lety +4

      AndDiracisHisProphet Well I've read your previous comments in many other math channels and they don't seem to be written by someone who doesn't understand
      No problem if you do them in German
      Don't say that you're ugly
      I personally don't care about that

    • @AndDiracisHisProphet
      @AndDiracisHisProphet Před 6 lety +5

      When you found my comments on other math channels you probably have already noticed that I make a lot of jokes. Not necessarily funny ones. The "ugly" comment was such a joke.
      Anyway, I indeed have planned doing math videos, but not using this user name (this is quite a private one), because I am an actual self employed tutor and I will use my companies name.
      Thing is I will mainly do stuff for grades 6 to 12, or so. Probably not so interesting for someone watching this kind of videos.

    • @marcioamaral7511
      @marcioamaral7511 Před 6 lety +5

      AndDiracisHisProphet But if one day you decide to do some calc, ODE, Linear álgebra. Abstract algebra vids
      You've got a subscriber!

  • @kokainum
    @kokainum Před 6 lety

    You can change the order because functions are non-negative. It doesn't need to converge. If you get infinity in one case, you get it also in the other.

  • @whatitmeans
    @whatitmeans Před 2 lety

    In complex numbers, if "s" is complex, e^(ns) != (e^s)^n... be aware of it because complex exponentiation is not a univocate value operation... so surely the relation is true for real "s", but for complex "s" you could find issues related to the multyvalued results of complex exponentiation

  • @stydras3380
    @stydras3380 Před 6 lety +1

    Awesome video! You can't swap integration and addition with this thing: ∫ ∑ x²(1-x²)ⁿ dx for x∈[-1; 1] when you sum over n c:

  • @_DD_15
    @_DD_15 Před 6 lety

    Your best video so far. Truly interesting!

  • @theonepath7865
    @theonepath7865 Před 6 lety +3

    You should record in 1080p 60fps. Quality res videos for quality maths 👌🏼

    • @AviMehra
      @AviMehra Před 6 lety

      TheOnePath he records on mac

    • @gian2kk
      @gian2kk Před 6 lety

      60fps sucks

  • @sergioh5515
    @sergioh5515 Před 6 lety

    Amazing and beautiful result! I always snapshot these kinds of things bc that are so interesting! Thanks for sharing as always!!!!!!!!!! 😇😇😇😇😇

  • @UnathiGX
    @UnathiGX Před 6 lety

    Wow...these things fascinate me...I don't know much about them...but the time will come I promise!

  • @charlievane
    @charlievane Před 2 lety +1

    Thanks

  • @SudarshanBaurai
    @SudarshanBaurai Před 2 lety

    You are simply awesome Prof. 🙏

  • @yousefalyousef59
    @yousefalyousef59 Před 4 lety

    Let the equation below accept a single solution(n) specify both(a,b) in terms of (n)
    f(x)=X^2-(a+b+1)X+(ab)=0
    since f(x)=0 is equivalent to
    x= (x-a)(x-b)
    I think in this space there are zeros of the zeta function .

  • @kylebrescher3189
    @kylebrescher3189 Před 6 lety

    I was getting ready to yell at you for casually swapping sums for integrals, but you passingly referred to absolute convergence. This is one of those I'll take your word for it :-)

    • @kylebrescher3189
      @kylebrescher3189 Před 6 lety +1

      After doing some homework of my own on this, it seems like a much safer assumption than I would have thought that you can make that kind of interchange. According to single-variable special cases of the Fubini/Tonelli theorems, if int(sum(|f(n))|) < inf, or sum(int(|f(n)|)), then the two are interchangeable for the entire function, sans absolute values.
      Tonelli's hinges on Fn(x) >= 0, and I start to lose the trail after that, but I think you're really quite safe. So if you found a function who had negative values and a sum which is conditionally convergent and married the two... maybe??
      Also, good job.
      Also also, can we get a LaTeX editor built into CZcams Comments?

  • @juanthegodlyhorse6647
    @juanthegodlyhorse6647 Před 2 lety +1

    proud to be a bose

  • @abdurrahimuzum5924
    @abdurrahimuzum5924 Před 6 lety +7

    this video very good. I want that you share such a this video. I'm wacthing from Turkey.

  • @ranjanadas3347
    @ranjanadas3347 Před 5 lety

    Hi, I'm from Bangladesh. I very much like your videos. Thanks for making video on Bose integral.

  • @d.h.y
    @d.h.y Před rokem

    10:35 Bravo!!!

  • @non-inertialobserver946
    @non-inertialobserver946 Před 6 lety +1

    Hi! I love your videos, and your math is on point Keep it up 😉

  • @davidblauyoutube
    @davidblauyoutube Před 2 lety

    Now, evaluate the integral using the residue theorem, thereby deriving the reflection formula for zeta!

  • @TimesOfSilence
    @TimesOfSilence Před 6 lety +2

    This. Is. Awesome.

  • @parnabghosh7877
    @parnabghosh7877 Před 6 lety +2

    That was a great one. How can we solve zeta(3)

  • @srikanthtupurani6316
    @srikanthtupurani6316 Před 5 lety +2

    Math is divine. Bose is a great scientist from India. In physics some elementary particles are called bosons.

  • @yousseffaryssy7760
    @yousseffaryssy7760 Před 3 lety

    thank very much you are a genius

  • @OonHan
    @OonHan Před 6 lety +1

    1 fact-oreo!
    Bringing back the fun

  • @dank9427
    @dank9427 Před 6 lety +1

    Small speaking mistake at 4:24, but still an awesome and creative video!

  • @sebastiangrander9002
    @sebastiangrander9002 Před 6 lety

    This is fucking amazing

  • @TheMauror22
    @TheMauror22 Před 6 lety +2

    WOW!! This is so cool!

  • @maxwelleinstein211
    @maxwelleinstein211 Před 6 lety

    U just solved the Riemann hypothesis

  • @Galileosays
    @Galileosays Před 4 lety

    Wow, an amazing proof. The ancient Greeks would be surprised to see Gamma, Zeta, Pi in one equation.

  • @BruceWayne-mk9km
    @BruceWayne-mk9km Před rokem

    This is awesome!!❤

  • @Archik4
    @Archik4 Před 6 lety

    zeta(3) = 1/2 integrate 0 to infinity u^2/(e^u-1) by u

  • @apta9931
    @apta9931 Před 6 lety +1

    I wonder what would happen if you did this with the eta function you just made a video on

  • @shandyverdyo7688
    @shandyverdyo7688 Před 5 lety

    We need more videos about this,,, BPRP!!!!!!!!!!!!!
    :V

  • @GeekTommy
    @GeekTommy Před 6 lety

    Great work, really interesting as always!

  • @cupanodensetsu2420
    @cupanodensetsu2420 Před 6 lety

    What a great video 😍😍😍
    Just like usual 😊

  • @marcioamaral7511
    @marcioamaral7511 Před 6 lety

    Each and every day you look like Dr Peyam
    High level maths!

  • @user-mt9ux2di6u
    @user-mt9ux2di6u Před 4 lety

    Blackpenredpen, I am pretty sure that you can always switch the order of summation and integration

  • @iprogramplus
    @iprogramplus Před 6 lety

    you are very cool and very educational

  • @sab1862
    @sab1862 Před 6 lety +8

    Bernhard Riemann!

  • @akashsardar495
    @akashsardar495 Před 5 lety

    Wow Bose Integral🤩

  • @phyarth8082
    @phyarth8082 Před 4 lety +1

    Bose condensate. is winter coming ? :)

  • @tutordave
    @tutordave Před 9 měsíci

    Does this formula work on the critical strip? Trying to graph |zeta(s)| as a function of x + iy (3D plot) did not seem to work. Maybe it's the program I'm using. Also, when I put in the first non-trivial zero of the zeta function, this formula you have does not return zero, so I think maybe it does not work on the critical strip... sadly. The function Riemann gives defines the zeta function in terms of the zeta function of 1-s. And when a function is defined using itself (sort of)... that's where the issues arise. My opinion. I wish there were a better form of the zeta function that did not do that.

  • @muradali9324
    @muradali9324 Před 3 lety

    😘😘ابداع يا استاد .احسنت 👏

  • @factsheet4930
    @factsheet4930 Před 6 lety +2

    2:06 apparently you sound exactly like me according to my phone. You saying "and take a look" in the video triggered my "Ok Google" command and searched for "look". :l

  • @eta3323
    @eta3323 Před 6 lety +4

    I do not really understand when and why you are allowed to change summation and integration. Can anyone explain is to me?

    • @Koisheep
      @Koisheep Před 6 lety

      ζeta if the integral is absolutely convergent (the integral of the absolute value is finite)

    • @eta3323
      @eta3323 Před 6 lety

      Thank you, but I was rather talking about why you're not allowed to change if the sum is divergent

    • @sergioh5515
      @sergioh5515 Před 6 lety +1

      ζeta if a function can be expressed as an infinite series and if it has a radius convergence, and if f(x) is differentiable and can be integrated.... then you are allowed to perform calculus on the series which means treating terms like constants and variables of integration. Meaning you can interchange the summation and integration. However you will have to find a proof of this theorem :)

    • @joelrzgn
      @joelrzgn Před 6 lety

      Because the integral and sum operators are linear and are operating on distinct variables.

    • @joelrzgn
      @joelrzgn Před 6 lety

      ζeta www.maths.manchester.ac.uk/~mdc/old/341/not7.pdf

  • @medgazzeh9884
    @medgazzeh9884 Před 4 lety

    To permutate the infinite sum and the proper integral, shouldn't the sum converge uniformely and not only absolutely??

  • @EyadAmmari
    @EyadAmmari Před 2 lety

    Amazing

  • @maximilianmueller4707
    @maximilianmueller4707 Před 5 lety

    Does anybody know the feeling of Depression i have it at the Ende of the Video it is so good why it has to be so good thanks for showing

  • @palakagarwal9819
    @palakagarwal9819 Před 5 lety

    Just amazing...

  • @strangeranjan
    @strangeranjan Před 3 lety +1

    Just thinking how he hold 2 pens together and switch them while writing.....

  • @agsnewton999
    @agsnewton999 Před 6 lety +1

    We know that zeta(2) = π^2/6, but can you show us how to calculate zeta(3) or zeta(4) maybe? I always wonder how to find the value of it..

    • @agsnewton999
      @agsnewton999 Před 6 lety

      Also when s > 2

    • @davidrheault7896
      @davidrheault7896 Před 6 lety

      Zeta(4) is equal to pi^4/90 ( The great Euler found them all)

    • @agsnewton999
      @agsnewton999 Před 6 lety

      David Rheault i already know the value. But i want to know how to find the pi^4/90 hahah

    • @davidrheault7896
      @davidrheault7896 Před 6 lety +1

      Fourier and parseval identity on f(x) = x^2, big formula, and you get zeta(4) as a function of zeta(2)

    • @akirakato1293
      @akirakato1293 Před 6 lety

      didnt he basically prove all the even values of zeta

  • @conrad5342
    @conrad5342 Před rokem

    As Gamma of negative integer values produces poles, I am wondering how one can define zeta there.

    • @vascomanteigas9433
      @vascomanteigas9433 Před 5 měsíci

      Use the integral to plot a keyhole contour over the complex plane, then use the Cauchy Residue Theorem and the Zeta Functional Equation are derived. The Analytical Continuation of Zeta are derived.

  • @theverymodelofamodernmajor6200

    4:17 I’m confused, if T(x) is defined in terms of n how can you pull it out of the summation?

  • @ryanchatterjee
    @ryanchatterjee Před 6 lety

    Are you going off HM Edwards' "Riemann's Zeta Function"? I'm reading it now and this is in one of the first few chapters.

  • @cameronspalding9792
    @cameronspalding9792 Před 4 lety

    Can we not do something similar with the eta function

  • @arekkrolak6320
    @arekkrolak6320 Před 2 lety

    I wonder if zeta is defined on the complex plane and your integral is defined on the real line can this be somehow accorded...

  • @debdhritiroy6868
    @debdhritiroy6868 Před 6 lety

    Hold on, x is always a variable, I think it should primarily be converted into something with u.. unless u r doin partial integration, which doean't seem to be the case, is it?

  • @suchetandontha3340
    @suchetandontha3340 Před 6 lety

    Hey nice video! But I just have one question; when saying a geometric series has the sum of a/(1-r), doesn't the sum need to start at 0 and not 1 like it did in the video?

    • @blackpenredpen
      @blackpenredpen  Před 6 lety +1

      Suchetan Dontha it depends. That's why I put down "first"/(1-r)

  • @casa1420
    @casa1420 Před 5 lety

    Very good!

  • @Saturos02
    @Saturos02 Před 6 lety

    Very nice!

  • @Galileo2pi
    @Galileo2pi Před 6 lety

    Wonderful

  • @andresxj1
    @andresxj1 Před 6 lety +2

    Just to be sure, since *u* has to be greater than 0, should the integral be from *a* to *infinity* and then take the limit of *a -> 0* ?

    • @AviMehra
      @AviMehra Před 6 lety +2

      Andy Arteaga yes but because it is continuous, the value equals the limit, given that the value (inside) exists. It does exist (of course, it was calculated) so the value is the same

  • @DiegoJove
    @DiegoJove Před 5 lety

    t=n*u then -t= -1(n*u) or = -t=-n*-u

  • @Patapom3
    @Patapom3 Před 6 lety

    Love it!

  • @izakj5094
    @izakj5094 Před 6 lety

    beautiful

  • @BabyXGlitz
    @BabyXGlitz Před 6 lety

    very enjoyable

  • @rsassine
    @rsassine Před 6 lety

    Thanks.

  • @holyshit922
    @holyshit922 Před 2 lety

    Steve did you forget umlaut on the name of this integral ?

  • @user-rz3id7nm6s
    @user-rz3id7nm6s Před 5 lety

    Great

  • @Tomaplen
    @Tomaplen Před 5 lety

    what if you have gamma(x)*zeta(y)
    or even maybe gamma(x)*zeta(2x) or something like that.
    Can you do anything?

  • @MustafaTAli
    @MustafaTAli Před 6 lety

    Please solve integration root Sin(x) dx by udv ?

  • @andreamonteroso8586
    @andreamonteroso8586 Před 4 lety

    thats cool...

  • @surjeetsingh1729iitk
    @surjeetsingh1729iitk Před 5 lety

    It should be uniformaly convergent bro then u can switch

  • @henrykwieniawski7233
    @henrykwieniawski7233 Před 6 lety

    Can you find ∫0→∞(-cosx/x^sinx)*x^e^x^cscx? I tried to find it using an integral calculator, but it gives me no answer. :(

  • @mohammedhubail1607
    @mohammedhubail1607 Před 6 lety

    4:25 x to the nth power

  • @mustafakemalturak1774
    @mustafakemalturak1774 Před 5 lety

    perfect

  • @elijahmurray6810
    @elijahmurray6810 Před 6 lety

    Couldn’t you rearrange this to come up with a continuation of the zeta function?

  • @The13mahfuz
    @The13mahfuz Před 4 lety

    Plz, define the limit of x.

  • @samholt9177
    @samholt9177 Před 2 lety

    Maths is cool.