Pure Mathematics: Recent submissions

Now showing items 76-80 of 90

    • Generators and relations for subsemigroups via boundaries in Cayley graphs 

      Gray, R; Ruskuc, Nik (2011-11) - Journal article
      Given a finitely generated semigroup S and subsemigroup T of S we define the notion of the boundary of T in S which, intuitively, describes the position of T inside the left and right Cayley graphs of S. We prove that if ...

    • Directed graph iterated function systems 

      Boore, Graeme C. (University of St Andrews, 2011-11-30) - Thesis
      This thesis concerns an active research area within fractal geometry. In the first part, in Chapters 2 and 3, for directed graph iterated function systems (IFSs) defined on ℝ, we prove that a class of 2-vertex directed ...

    • Presentations of inverse semigroups, their kernels and extensions 

      Carvalho, C.A.; Gray, R; Ruskuc, Nik (2011-06-01) - Journal article
      Let S be an inverse semigroup and let π:S→T be a surjective homomorphism with kernel K. We show how to obtain a presentation for K from a presentation for S, and vice versa. We then investigate the relationship between the ...

    • Simple extensions of combinatorial structures 

      Brignall, R; Ruskuc, Nik; Vatter, V (2011-07) - Journal article
      An interval in a combinatorial structure R is a set I of points which are related to every point in R \ I in the same way. A structure is simple if it has no proper intervals. Every combinatorial structure can be expressed ...

    • A commutative noncommutative fractal geometry 

      Samuel, Anthony (University of St Andrews, 2010) - Thesis
      In this thesis examples of spectral triples, which represent fractal sets, are examined and new insights into their noncommutative geometries are obtained. Firstly, starting with Connes' spectral triple for a non-empty ...