Displaying 361 – 380 of 446

Showing per page

The mean square of the divisor function

Chaohua Jia, Ayyadurai Sankaranarayanan (2014)

Acta Arithmetica

Let d(n) be the divisor function. In 1916, S. Ramanujan stated without proof that n x d ² ( n ) = x P ( l o g x ) + E ( x ) , where P(y) is a cubic polynomial in y and E ( x ) = O ( x 3 / 5 + ε ) , with ε being a sufficiently small positive constant. He also stated that, assuming the Riemann Hypothesis (RH), E ( x ) = O ( x 1 / 2 + ε ) . In 1922, B. M. Wilson proved the above result unconditionally. The direct application of the RH would produce E ( x ) = O ( x 1 / 2 ( l o g x ) l o g l o g x ) . In 2003, K. Ramachandra and A. Sankaranarayanan proved the above result without any assumption. In this paper, we prove E ( x ) = O ( x 1 / 2 ( l o g x ) ) .

The mean value of |L(k,χ)|² at positive rational integers k ≥ 1

Stéphane Louboutin (2001)

Colloquium Mathematicae

Let k ≥ 1 denote any positive rational integer. We give formulae for the sums S o d d ( k , f ) = χ ( - 1 ) = - 1 | L ( k , χ ) | ² (where χ ranges over the ϕ(f)/2 odd Dirichlet characters modulo f > 2) whenever k ≥ 1 is odd, and for the sums S e v e n ( k , f ) = χ ( - 1 ) = + 1 | L ( k , χ ) | ² (where χ ranges over the ϕ(f)/2 even Dirichlet characters modulo f>2) whenever k ≥ 1 is even.

Currently displaying 361 – 380 of 446