• Title of article

    Density near zero

  • Author/Authors

    - - نويسنده Department of Mathematics, Faculty of Basic Science, Shahed University, Tehran, Iran. Bayatmanesh Elham , - - نويسنده Department of Mathematics, Faculty of Basic Science, Shahed University, Tehran, Iran. Akbari Tootkaboni Mohammad

  • Pages
    11
  • From page
    33
  • Abstract
    -
  • Abstract
    Let $S$ be a dense subsemigroup of $(0,+infty)$. In this paper, we state   definition of thick near zero, and also  we will introduce a definition that is equivalent to the definition of piecewise syndetic near zero which presented by Hindman  and Leader in cite{Hin-Lead}.  We define density near zero for subsets of $S$ by a collection of nonempty finite subsets of $S$ and we investigate the conditions under  these concepts.
  • Journal title
    Astroparticle Physics
  • Record number

    2410056