
Toka Diagana, Ph.D.
Professor
Address
Department of Mathematics
Howard University
Washington DC 20059
Office
ASB 209
ph: 2028067123
fax: 2028066831
email: tdiagana@howard.edu
My personal web page
Education
Ph. D. (1999) Université Claude Bernard  Lyon, France
Research Interests: Operator Theory; (padic) Functional Analysis ;
Abstract Differential Equations; Stochastic Differential Equations; Difference Equations; and Integrodifferential Equations.
Most interesting phenomena encountered in our daily life can be described through
differential equations. In recent years, my goal has been to
study the existence of solutions to abstract differential
equations in various classes of functions such as almost
periodic functions, almost automorphic functions, pseudo almost
periodic functions, pseudo almost automorphic functions as well
as weighted pseudo almost periodic functions we recently
introduced in the literature. One of my current goals consists
of studying singular and fractional differential equations in
connection with the abovementioned classes of functions.
It is wellknown that the best way to understand properties of linear
operators is through their spectral analysis. In particular, the spectral
theory for linear operators plays a crucial role in several fields
including quantum mechanics. Except for a few investigations such as the
pioneer work of Vishik, there is no general spectral theory for linear
operators in the nonarchimedean setting. One of my current goals consists
of developing a general spectral theory for unbounded linear operators on
nonarchimedean Banach spaces.
Latest Books
Almost automorphic type and almost periodic type functions in abstract spaces, Springer, New York, 2013
Almost Periodic Stochastic Processes, Springer, New York, 2011 (with P. H. Bezandry)
Pseudo Almost Periodic Functions in Banach Spaces, Nova Science Publishers, New York, 2007
Selected Publications
 Existence of pseudo almost automorphic mild solutions to some nonautonomous second order differential equations. Rocky Mt. J. Math. 43 (2013), No. 3, 793824.
 (with P. H. Bezandry) SquareMean Almost Periodic Solutions to Some Classes of Nonautonomous Stochastic Evolution Equations With Finite Delay. J. Appl. Funct. Anal. 7 (2012), no. 4, 345366.
 Existence of globally attracting almost automorphic solutions to some nonautonomous higherorder difference equations, Appl. Math. Comput. 219 (2013), no. 12, 65106519.
 Bounded solutions to some classes of nonautonomous higherorder differential equations. Afr. Mat. 24 (2013), No. 1, 3353.
 Existence Results for Some HigherOrder Evolution Equations with TimeDependent Unbounded Operator Coefficients. Mathematica Slovaca. 2013. To appear.
 Almost automorphic solutions to some damped secondorder differential equations. Commun. Nonlinear Sci. Numer. Simul. 17 (2012), no. 11, 40744084.
 Almost periodic solutions to some secondorder nonautonomous differential equations. Proc. Amer. Math. Soc. 140 (2012), no. 1, 279289.
 Pseudoalmost periodic solutions for some classes of nonautonomous partial evolutions equations. J. Franklin Inst. 348 (2011), no. 8, 2082  2098.
 Almost periodic solutions for some higherorder nonautonomous differential equations with operator coefficients. Math. Comput. Modeling 54 (2011), no. 1112, 2672  2685.
 Existence of weighted pseudo almost periodic solutions to some classes of hyperbolic evolution equations. J. Math. Anal. Appl. 350 (2009), no. 1, 1828.
 (with M. Baroun, S. Boulite, and L. Maniar), Almost periodic solutions to some semilinear nonautonomous thermoelastic plate equations. J. Math. Anal. Appl. 349 (2009), no. 1, 7484.
 (with H. Henriquez and E. Hernandez), Asymptotically almost periodic solutions to some classes of secondorder functional differential equations. Differential Integral Equations 21 (2008), no. 56, 575600.
Editorship
Associate Editor for the following mathematical journals:
 Abstract and Applied Analysis (AAA)
 Advances in Difference Equations (ADE)
 Advances in Differential Equations and Control Processes(ADECP)
 Advances in Theoretical and Applied Mathematics(ATAM)
 Afrika Matematika
 Involve: A Journal of Mathematics
 International Journal of Differential Equations(IJDE)
 Journal of Nonlinear Evolution Equations and Applications
 Journal of Mathematical Control Science and Applications
 International Journal of Statistika and Mathematika
EditorinChief of the following mathematical journal:
 Nonautonomous and Stochastic Dynamical Systems
Founding (Managing) Editor for the following mathematical journals:
 Communications in Mathematical Analysis (CMA)
 Journal of Abstract Differential Equations and Applications (JADEA)
 African Diaspora Journal Of Mathematics (ADJM)
