General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms Explicit estimates: from Λ(n) in arithmetic progressions to Λ(n)/nMarch 5, 2015
AbstractWe denote byψ(x; q, a) the sum of Λ(n)/n for all n ≤ x and congruent to a mod q and similary by ψ(x; q, a) the sum of Λ(n) over the same set. We show that the error term inψ(x; q, a)−(log x)/ϕ(q)− C(q, a), for a suitable constant C(q, a) can be controlled by that of ψ(y; q, a) − y/ϕ(q) for y of size x, up to a small error term. As a consequence, if a partial Generalized Riemann Hypothesis has been verified for the L-functions attached to primitive characters modulo q up to height H, this error term is bounded by O(e −H ) when x ≥ H. Previous methods had at best O(1/H) instead. We further compute asymptotics for the L 2 -average of quantity closely related to C(q, a).