Is this Riemann integral for prime numbers true?

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While answering another question in MSE, I had used the following result which I thought was a trivial consequence of the prime number theorem and equidistribution. However, I realized from the comments that many people thought that this was not either true or counter intuitive. Hence I am posting this as a question looking for a proof or disproof.




Let $p_k$ be the $k$-th prime and let $f$ be a continuous function Riemann
integrable in $(0,1)$ then,



$$ lim_n to inftyfrac1nsum_r = 1^nfBig(fracp_rp_nBig) = int_0^1f(x)dx. $$




My proof was based on showing that as $n to infty$, the ratios $p_r/p_n$ approached equidistribution in $(0,1)$ hence the integral follows as a trivial property of equidistributed sequence.



Motivation: I have found countless identities, limits etc on prime numbers using this simple formula, including all answers to all three questions on the arithmetic, geometric and harmonic means of primes mentioned in the above link.










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  • 2




    If you take the example $f(x)=2x$, then the right-hand side is just one. However, for a huge (fixed) value of $n$, there would be more primes in the interval $[0,p_n/2]$ than in the interval $[p_n/2,p_n]$, so why whould the value of that average be near the number one? ADDITION: As an example, among the first half billion numbers there are 26355867 primes, but among the next half billion numbers, i.e. between $0.5cdot 10^9$ and $10^9$, there are only 24491667 primes.
    – Jeppe Stig Nielsen
    2 hours ago







  • 1




    @JeppeStigNielsen How do you know that the first interval will have more primes asymptotically?
    – Yanko
    2 hours ago






  • 1




    @JeppeStigNielsen I think the same as you. For me, it would look nicer, if one changes $dx$ by another integrator (kinda Riemann-Stieltjes) related to the distribution of primes.
    – Marcuswood
    2 hours ago






  • 2




    @JeppeStigNielsen use the prime number theorem: $pi(n)/pi(2n)approx (n/log (n))/(2nlog(2n)) = 1/2 (log(2)+log(n))/log(n)to 1/2$
    – Bananach
    2 hours ago







  • 1




    @Marcuswood the prime number theorem says that F(x)=x indeed. This is essentially because the "average gap" $log x$ between prime numbers is a slowly varying function, too slow to matter when the numbers of prime numbers at $n$ and $x n$ are considered with $ntoinfty$.
    – Bananach
    2 hours ago















up vote
7
down vote

favorite
7












While answering another question in MSE, I had used the following result which I thought was a trivial consequence of the prime number theorem and equidistribution. However, I realized from the comments that many people thought that this was not either true or counter intuitive. Hence I am posting this as a question looking for a proof or disproof.




Let $p_k$ be the $k$-th prime and let $f$ be a continuous function Riemann
integrable in $(0,1)$ then,



$$ lim_n to inftyfrac1nsum_r = 1^nfBig(fracp_rp_nBig) = int_0^1f(x)dx. $$




My proof was based on showing that as $n to infty$, the ratios $p_r/p_n$ approached equidistribution in $(0,1)$ hence the integral follows as a trivial property of equidistributed sequence.



Motivation: I have found countless identities, limits etc on prime numbers using this simple formula, including all answers to all three questions on the arithmetic, geometric and harmonic means of primes mentioned in the above link.










share|cite|improve this question



















  • 2




    If you take the example $f(x)=2x$, then the right-hand side is just one. However, for a huge (fixed) value of $n$, there would be more primes in the interval $[0,p_n/2]$ than in the interval $[p_n/2,p_n]$, so why whould the value of that average be near the number one? ADDITION: As an example, among the first half billion numbers there are 26355867 primes, but among the next half billion numbers, i.e. between $0.5cdot 10^9$ and $10^9$, there are only 24491667 primes.
    – Jeppe Stig Nielsen
    2 hours ago







  • 1




    @JeppeStigNielsen How do you know that the first interval will have more primes asymptotically?
    – Yanko
    2 hours ago






  • 1




    @JeppeStigNielsen I think the same as you. For me, it would look nicer, if one changes $dx$ by another integrator (kinda Riemann-Stieltjes) related to the distribution of primes.
    – Marcuswood
    2 hours ago






  • 2




    @JeppeStigNielsen use the prime number theorem: $pi(n)/pi(2n)approx (n/log (n))/(2nlog(2n)) = 1/2 (log(2)+log(n))/log(n)to 1/2$
    – Bananach
    2 hours ago







  • 1




    @Marcuswood the prime number theorem says that F(x)=x indeed. This is essentially because the "average gap" $log x$ between prime numbers is a slowly varying function, too slow to matter when the numbers of prime numbers at $n$ and $x n$ are considered with $ntoinfty$.
    – Bananach
    2 hours ago













up vote
7
down vote

favorite
7









up vote
7
down vote

favorite
7






7





While answering another question in MSE, I had used the following result which I thought was a trivial consequence of the prime number theorem and equidistribution. However, I realized from the comments that many people thought that this was not either true or counter intuitive. Hence I am posting this as a question looking for a proof or disproof.




Let $p_k$ be the $k$-th prime and let $f$ be a continuous function Riemann
integrable in $(0,1)$ then,



$$ lim_n to inftyfrac1nsum_r = 1^nfBig(fracp_rp_nBig) = int_0^1f(x)dx. $$




My proof was based on showing that as $n to infty$, the ratios $p_r/p_n$ approached equidistribution in $(0,1)$ hence the integral follows as a trivial property of equidistributed sequence.



Motivation: I have found countless identities, limits etc on prime numbers using this simple formula, including all answers to all three questions on the arithmetic, geometric and harmonic means of primes mentioned in the above link.










share|cite|improve this question















While answering another question in MSE, I had used the following result which I thought was a trivial consequence of the prime number theorem and equidistribution. However, I realized from the comments that many people thought that this was not either true or counter intuitive. Hence I am posting this as a question looking for a proof or disproof.




Let $p_k$ be the $k$-th prime and let $f$ be a continuous function Riemann
integrable in $(0,1)$ then,



$$ lim_n to inftyfrac1nsum_r = 1^nfBig(fracp_rp_nBig) = int_0^1f(x)dx. $$




My proof was based on showing that as $n to infty$, the ratios $p_r/p_n$ approached equidistribution in $(0,1)$ hence the integral follows as a trivial property of equidistributed sequence.



Motivation: I have found countless identities, limits etc on prime numbers using this simple formula, including all answers to all three questions on the arithmetic, geometric and harmonic means of primes mentioned in the above link.







integration number-theory analysis definite-integrals prime-numbers






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share|cite|improve this question













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edited 1 hour ago

























asked 3 hours ago









Nilotpal Kanti Sinha

3,61021334




3,61021334







  • 2




    If you take the example $f(x)=2x$, then the right-hand side is just one. However, for a huge (fixed) value of $n$, there would be more primes in the interval $[0,p_n/2]$ than in the interval $[p_n/2,p_n]$, so why whould the value of that average be near the number one? ADDITION: As an example, among the first half billion numbers there are 26355867 primes, but among the next half billion numbers, i.e. between $0.5cdot 10^9$ and $10^9$, there are only 24491667 primes.
    – Jeppe Stig Nielsen
    2 hours ago







  • 1




    @JeppeStigNielsen How do you know that the first interval will have more primes asymptotically?
    – Yanko
    2 hours ago






  • 1




    @JeppeStigNielsen I think the same as you. For me, it would look nicer, if one changes $dx$ by another integrator (kinda Riemann-Stieltjes) related to the distribution of primes.
    – Marcuswood
    2 hours ago






  • 2




    @JeppeStigNielsen use the prime number theorem: $pi(n)/pi(2n)approx (n/log (n))/(2nlog(2n)) = 1/2 (log(2)+log(n))/log(n)to 1/2$
    – Bananach
    2 hours ago







  • 1




    @Marcuswood the prime number theorem says that F(x)=x indeed. This is essentially because the "average gap" $log x$ between prime numbers is a slowly varying function, too slow to matter when the numbers of prime numbers at $n$ and $x n$ are considered with $ntoinfty$.
    – Bananach
    2 hours ago













  • 2




    If you take the example $f(x)=2x$, then the right-hand side is just one. However, for a huge (fixed) value of $n$, there would be more primes in the interval $[0,p_n/2]$ than in the interval $[p_n/2,p_n]$, so why whould the value of that average be near the number one? ADDITION: As an example, among the first half billion numbers there are 26355867 primes, but among the next half billion numbers, i.e. between $0.5cdot 10^9$ and $10^9$, there are only 24491667 primes.
    – Jeppe Stig Nielsen
    2 hours ago







  • 1




    @JeppeStigNielsen How do you know that the first interval will have more primes asymptotically?
    – Yanko
    2 hours ago






  • 1




    @JeppeStigNielsen I think the same as you. For me, it would look nicer, if one changes $dx$ by another integrator (kinda Riemann-Stieltjes) related to the distribution of primes.
    – Marcuswood
    2 hours ago






  • 2




    @JeppeStigNielsen use the prime number theorem: $pi(n)/pi(2n)approx (n/log (n))/(2nlog(2n)) = 1/2 (log(2)+log(n))/log(n)to 1/2$
    – Bananach
    2 hours ago







  • 1




    @Marcuswood the prime number theorem says that F(x)=x indeed. This is essentially because the "average gap" $log x$ between prime numbers is a slowly varying function, too slow to matter when the numbers of prime numbers at $n$ and $x n$ are considered with $ntoinfty$.
    – Bananach
    2 hours ago








2




2




If you take the example $f(x)=2x$, then the right-hand side is just one. However, for a huge (fixed) value of $n$, there would be more primes in the interval $[0,p_n/2]$ than in the interval $[p_n/2,p_n]$, so why whould the value of that average be near the number one? ADDITION: As an example, among the first half billion numbers there are 26355867 primes, but among the next half billion numbers, i.e. between $0.5cdot 10^9$ and $10^9$, there are only 24491667 primes.
– Jeppe Stig Nielsen
2 hours ago





If you take the example $f(x)=2x$, then the right-hand side is just one. However, for a huge (fixed) value of $n$, there would be more primes in the interval $[0,p_n/2]$ than in the interval $[p_n/2,p_n]$, so why whould the value of that average be near the number one? ADDITION: As an example, among the first half billion numbers there are 26355867 primes, but among the next half billion numbers, i.e. between $0.5cdot 10^9$ and $10^9$, there are only 24491667 primes.
– Jeppe Stig Nielsen
2 hours ago





1




1




@JeppeStigNielsen How do you know that the first interval will have more primes asymptotically?
– Yanko
2 hours ago




@JeppeStigNielsen How do you know that the first interval will have more primes asymptotically?
– Yanko
2 hours ago




1




1




@JeppeStigNielsen I think the same as you. For me, it would look nicer, if one changes $dx$ by another integrator (kinda Riemann-Stieltjes) related to the distribution of primes.
– Marcuswood
2 hours ago




@JeppeStigNielsen I think the same as you. For me, it would look nicer, if one changes $dx$ by another integrator (kinda Riemann-Stieltjes) related to the distribution of primes.
– Marcuswood
2 hours ago




2




2




@JeppeStigNielsen use the prime number theorem: $pi(n)/pi(2n)approx (n/log (n))/(2nlog(2n)) = 1/2 (log(2)+log(n))/log(n)to 1/2$
– Bananach
2 hours ago





@JeppeStigNielsen use the prime number theorem: $pi(n)/pi(2n)approx (n/log (n))/(2nlog(2n)) = 1/2 (log(2)+log(n))/log(n)to 1/2$
– Bananach
2 hours ago





1




1




@Marcuswood the prime number theorem says that F(x)=x indeed. This is essentially because the "average gap" $log x$ between prime numbers is a slowly varying function, too slow to matter when the numbers of prime numbers at $n$ and $x n$ are considered with $ntoinfty$.
– Bananach
2 hours ago





@Marcuswood the prime number theorem says that F(x)=x indeed. This is essentially because the "average gap" $log x$ between prime numbers is a slowly varying function, too slow to matter when the numbers of prime numbers at $n$ and $x n$ are considered with $ntoinfty$.
– Bananach
2 hours ago











1 Answer
1






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up vote
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Too long for a comment



Divide $[0,1]$ into $$[0,p_1/p_n],[p_1/p_n,p_2/p_n],cdots,[p_n-1/p_n,1]$$



Then, using Riemann sum, we have
$$I:=int^1_0f(x)dx=lim_ntoinftysum^n_k=1fleft(fracp_kp_nright)fracp_k+1-p_kp_n$$



If we assume that $p_j=jln j$,
$$I=lim_ntoinftysum^n_k=1fleft(fracp_kp_nright)h(k,n)+lim_ntoinftyfrac1n sum^n_k=1fleft(fracp_kp_nright) qquad(1)$$
where
$$h(k,n)=frac(k+1)ln(k+1)-kln knln n-frac1n$$



It can be shown that $$h(k,n)le h(n,n)=O(frac1nln n)$$



Therefore, the absolute value of the first term in $(1)$ is upper bounded by
$$h(n,n)cdot nMto 0$$ where $M$ is a positive constant. This leads us to our desired result.



I am not sure if this argument can be made rigorous. I will review it when I have leisure time.






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    up vote
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    down vote













    Too long for a comment



    Divide $[0,1]$ into $$[0,p_1/p_n],[p_1/p_n,p_2/p_n],cdots,[p_n-1/p_n,1]$$



    Then, using Riemann sum, we have
    $$I:=int^1_0f(x)dx=lim_ntoinftysum^n_k=1fleft(fracp_kp_nright)fracp_k+1-p_kp_n$$



    If we assume that $p_j=jln j$,
    $$I=lim_ntoinftysum^n_k=1fleft(fracp_kp_nright)h(k,n)+lim_ntoinftyfrac1n sum^n_k=1fleft(fracp_kp_nright) qquad(1)$$
    where
    $$h(k,n)=frac(k+1)ln(k+1)-kln knln n-frac1n$$



    It can be shown that $$h(k,n)le h(n,n)=O(frac1nln n)$$



    Therefore, the absolute value of the first term in $(1)$ is upper bounded by
    $$h(n,n)cdot nMto 0$$ where $M$ is a positive constant. This leads us to our desired result.



    I am not sure if this argument can be made rigorous. I will review it when I have leisure time.






    share|cite|improve this answer


























      up vote
      6
      down vote













      Too long for a comment



      Divide $[0,1]$ into $$[0,p_1/p_n],[p_1/p_n,p_2/p_n],cdots,[p_n-1/p_n,1]$$



      Then, using Riemann sum, we have
      $$I:=int^1_0f(x)dx=lim_ntoinftysum^n_k=1fleft(fracp_kp_nright)fracp_k+1-p_kp_n$$



      If we assume that $p_j=jln j$,
      $$I=lim_ntoinftysum^n_k=1fleft(fracp_kp_nright)h(k,n)+lim_ntoinftyfrac1n sum^n_k=1fleft(fracp_kp_nright) qquad(1)$$
      where
      $$h(k,n)=frac(k+1)ln(k+1)-kln knln n-frac1n$$



      It can be shown that $$h(k,n)le h(n,n)=O(frac1nln n)$$



      Therefore, the absolute value of the first term in $(1)$ is upper bounded by
      $$h(n,n)cdot nMto 0$$ where $M$ is a positive constant. This leads us to our desired result.



      I am not sure if this argument can be made rigorous. I will review it when I have leisure time.






      share|cite|improve this answer
























        up vote
        6
        down vote










        up vote
        6
        down vote









        Too long for a comment



        Divide $[0,1]$ into $$[0,p_1/p_n],[p_1/p_n,p_2/p_n],cdots,[p_n-1/p_n,1]$$



        Then, using Riemann sum, we have
        $$I:=int^1_0f(x)dx=lim_ntoinftysum^n_k=1fleft(fracp_kp_nright)fracp_k+1-p_kp_n$$



        If we assume that $p_j=jln j$,
        $$I=lim_ntoinftysum^n_k=1fleft(fracp_kp_nright)h(k,n)+lim_ntoinftyfrac1n sum^n_k=1fleft(fracp_kp_nright) qquad(1)$$
        where
        $$h(k,n)=frac(k+1)ln(k+1)-kln knln n-frac1n$$



        It can be shown that $$h(k,n)le h(n,n)=O(frac1nln n)$$



        Therefore, the absolute value of the first term in $(1)$ is upper bounded by
        $$h(n,n)cdot nMto 0$$ where $M$ is a positive constant. This leads us to our desired result.



        I am not sure if this argument can be made rigorous. I will review it when I have leisure time.






        share|cite|improve this answer














        Too long for a comment



        Divide $[0,1]$ into $$[0,p_1/p_n],[p_1/p_n,p_2/p_n],cdots,[p_n-1/p_n,1]$$



        Then, using Riemann sum, we have
        $$I:=int^1_0f(x)dx=lim_ntoinftysum^n_k=1fleft(fracp_kp_nright)fracp_k+1-p_kp_n$$



        If we assume that $p_j=jln j$,
        $$I=lim_ntoinftysum^n_k=1fleft(fracp_kp_nright)h(k,n)+lim_ntoinftyfrac1n sum^n_k=1fleft(fracp_kp_nright) qquad(1)$$
        where
        $$h(k,n)=frac(k+1)ln(k+1)-kln knln n-frac1n$$



        It can be shown that $$h(k,n)le h(n,n)=O(frac1nln n)$$



        Therefore, the absolute value of the first term in $(1)$ is upper bounded by
        $$h(n,n)cdot nMto 0$$ where $M$ is a positive constant. This leads us to our desired result.



        I am not sure if this argument can be made rigorous. I will review it when I have leisure time.







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited 2 hours ago

























        answered 2 hours ago









        Szeto

        4,9811623




        4,9811623



























             

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