Maseno University Repository

Department of Mathematics

Department of Mathematics

 

Recent Submissions

  • Paul O Oleche, John O Agure (Int. Journal of Math. Analysis,, 2010)
    A closed densely defined operator H, on a Banach space X, whose spectrum is contained in R and satisfies (z − H)−1 ≤ c z α | z|β ∀ z ∈ R with z α := |z|2 + 1 (1) for some α , β ≥ 0; c > 0, is said to ...
  • JO Agure (Cambridge University Press, 1996-02)
    This paper investigates a certain type of numerical range introduced by Stampfli. In particular, we investigate the convexity of this set of elements of operators on Hilbert spaces and its relationship to the algebra ...
  • JO Bonyo, JO Agure (Int J Math Anal, 2010)
    We characterize when the norm of inner derivation on a norm ideal equals that on the quotient algebra. We further investigate norms of inner derivations implemented by normal and hyponormal operators on norm ...
  • JO Bonyo, JO Agure (Int. Journal of Math. Analysis, 2010)
    Let B(H) be the algebra of bounded linear operators on a Hilbert space H and J be a norm ideal in B(H). We investigate the relationship between the diameter of the numerical range of an operator A ∈ B(H) and the norm ...
  • Shem Aywa, JO Agure, W Rao (Vdm verlag Dr. Muller aktiengeselischaft & co. kg., 2010)
    A sequence (uj)j2N of operators in L(X; Y ) is a (p; q)-summing multi- plier (or (p; q)-summing sequence of operators), in short (uj) 2 `¼p;q (X; Y ), if there exists a constant C > 0 such that, for any ¯nite collection ...
  • NB Okelo, JO Agure (SAMSA 2012 mathematics conference proceedings, 2012-11)
    Malaria is a major public health concern, especially among pregnant women and children under the age of five. It is a leading cause of morbidity and mortality in Malawi, accounting for fourty percent of out-patient ...
  • John Ogonji Agure, David Otieno Ambogo, Fredrick Oluoch Nyamwala (WILEY‐VCH Verlag, 2013-03)
    Using subspace theory together with appropriate smoothness and decay conditions, we calculated the deficiency indices and absolutely continuous spectrum of fourth order difference equations with unbounded coefficients. In ...
  • Denis Njue Kingangi, John Ogoji Agure, Fredrick Oluoch Nyamwala (Scientific Research Publishing, 2014-07-07)
    The norm of an elementary operator has been studied by many mathematicians. Varied results have been established especially on the lower bound of this norm. Here, we attempt the same problem for finite dimensional operators.
  • FM Runji, JO Agure, FO Nyamwala (HIKARI Ltd,, 2017)
    We examine the relationship between the numerical range of the restriction of a generalized derivation to a norm ideal J and that of its implementing elements. Mathematics Subject Classi cation: 47A12; 47B47
  • Flora Mati Runji, John Ogonji Agure, Fredrick Oluoch Nyamwala (Academic Publications, Ltd., 2017-02)
    The notion of the numerical range has been generalized in different directions. One such direction, is the maximal numerical range introduced by Stampfli (1970) to derive an identity for the norm of a derivation on L(H). ...
  • Micheal Babatunde Oguntola, Mathew Ngugi Kinyanjui, John Agure Ogonji (Global Journal of Pure and Applied Mathematics, 2018)
    In this paper, we investigate the importance of structural viscoelasticity in the mechanical response of deformable porous media with incompressible constituents under sudden changes in the external applied quasi-static ...
  • Donnie Munyao Kasyoki (African Institute for Mathematical Sciences, Master Thesis, 2013-05-23)
    In this research project, we seek to address the problem of deciding which nite simple graph is a prime graph of a nite group. In particular, we only focus on showing which 4-regular graphs can be prime graphs of some ...
  • Paul O Oleche, Naftali O Ongati, John O Agure (JOOUST, 2009)
    A bounded operator with the spectrum lying in a compact set V ⊂ R, has C∞(V ) functional calculus. On the other hand, an operator H acting on a Hilbert space H, admits a C(R) functional calculus if H is self-adjoint. So ...
  • Paul O Oleche, N Omolo-Ongati, John O Agure (International Journal of Pure and Applied Mathematics, 2009-03)
    A closed densely defined operator H, on a Banach space X, whose spectrum is contained in R and satisfies
  • John O Agure, Paul O Oleche (Int. Journal of Math, 2010)
    This paper follows [1] in the quantitative study of Numerical Ranges introduced by Stampfli [9]. In particular, we consider a family of mutually orthogonal projections and investigate how a numerical range can be related ...
  • Mugisha Joseph Ong’ala Jacob Otieno, Oleche Paul (2013)
    There are major advances which have been made to understand the epidemiology of infectious diseases. However, more than 2 million children in the developing countries still die from pneumonia each year. The efforts to ...
  • NB Okelo, JO Agure, PO Oleche (Elsevier, 2013-09-01)
    In this paper, we present various notions and aspects of orthogonality in normed spaces. Characterizations and generalizations of orthogonality are also considered. Results on orthogonality of the range and the kernel of ...
  • DO Adicka, W Mukuna, PO Oleche (Hikari Ltd, 2014)
    In this paper, we give a characterization of scalar operators. In particular we show that a densely defined closed linear operator H acting on a reflexive Banach space X is scalar if it is of (0, 1) type R and f (H)≤ f∞ ...
  • J Otieno, JYT Mugisha, BK Nannyonga, P Oleche (HIKARI Ltd, 2014)
    In this paper we study the disease dynamics of trypanosomiasis in a cattle population. The compartmental model presented includes the wild animal population which provides an alternative feeding source for the tsetse ...

View more