Prime-counting Function - History

History

Of great interest in number theory is the growth rate of the prime-counting function. It was conjectured in the end of the 18th century by Gauss and by Legendre to be approximately

in the sense that

This statement is the prime number theorem. An equivalent statement is

where li is the logarithmic integral function. The prime number theorem was first proved in 1896 by Jacques Hadamard and by Charles de la Vallée Poussin independently, using properties of the Riemann zeta function introduced by Riemann in 1859.

More precise estimates of are now known; for example

where the O is big O notation. For most values of we are interested in (i.e., when is not unreasonably large) is greater than, but infinitely often the opposite is true. For a discussion of this, see Skewes' number.

Proofs of the prime number theorem not using the zeta function or complex analysis were found around 1948 by Atle Selberg and by Paul Erdős (for the most part independently).

Read more about this topic:  Prime-counting Function

Famous quotes containing the word history:

    “The awareness that health is dependent upon habits that we control makes us the first generation in history that to a large extent determines its own destiny.”
    —Jimmy Carter (James Earl Carter, Jr.)

    “The steps toward the emancipation of women are first intellectual, then industrial, lastly legal and political. Great strides in the first two of these stages already have been made of millions of women who do not yet perceive that it is surely carrying them towards the last.”
    —Ellen Battelle Dietrick, U.S. suffragist. As quoted in History of Woman Suffrage, vol. 4, ch. 13, by Susan B. Anthony and Ida Husted Harper (1902)

    “The basic idea which runs right through modern history and modern liberalism is that the public has got to be marginalized. The general public are viewed as no more than ignorant and meddlesome outsiders, a bewildered herd.”
    —Noam Chomsky (b. 1928)