Bonse's Inequality: Estimating Lower Bound on Prime Powers

  • Context: Graduate 
  • Thread starter Thread starter a1call
  • Start date Start date
  • Tags Tags
    Inequality
Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
2 replies · 2K views
a1call
Messages
90
Reaction score
5
Hi all,
https://en.m.wikipedia.org/wiki/Bonse's_inequality

It seems to me that the inequality can be true for higher powers (if not any given higher power), for an appropriately higher (lower) bound for "n".

Any thoughts, proofs, counter proofs your insights are appreciated.

In particular, I am interested in estimates (or preferably lower bound) for m for:

##(p-1)# < p^m##
where p is any prime number.

Thank you in advance.
 
Mathematics news on Phys.org
There is always a prime between n and 2n (https://en.wikipedia.org/wiki/Bertrand's_postulate]Bertrand's[/PLAIN] postulate, proved 1852), therefore ##p_n p_{n-1} p_{n-2} \dots > \frac{1}{2} p_{n+1} \frac{1}{2^2} p_{n+1} \frac{1}{2^3} p_{n+1} \dots##. As long as the product of the remaining primes is larger than 64, the product is larger than ##p_{n+1}^3##. That happens for 2*3*5*7, so 2*3*5*7*11*13*17 = 510510 > 6859 = 193 is the first number where the general proof works, but 2*3*5*7*11 > 13^3 is where the inequality starts being valid.

It should be obvious how to extend that to larger powers.

I'm surprised Bonse's inequality got a special name.
 
Last edited by a moderator:
Thank you very much mfb.
Typical exemplary reply.