Range of density measures

Abstract

We investigate some properties of density measures -- finitely additive measures on the set of natural numbers $\N$ extending asymptotic density. We introduce a class of density measures, which is defined using cluster points of the sequence $\big(\frac{A(n)}{n}\big)$ as well as cluster points of some other similar sequences. We obtain range of possible values of density measures for any subset of $\N$. Our description of this range simplifies the description of Bhashkara Rao and Bhashkara Rao \cite{brbr} for general finitely additive measures. Also the values which can be attained by the measures defined in the first part of the paper are studied.