21:38:56

**Prof. Toka Diagana**

Department of Mathematics

Howard University

2441 6th Street NW

Washington DC 20059

United States of America

Phone (office): 202-806-7123

Fax (dept.): 202-806-6831

E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

** RECENT AND/OR UPCOMING ACTIVITIES**

--- I will be a plenary speaker at the **CIMOM'18** (Colloque International: "La modelisation mathematique dans le contexte de Mayotte et de sa region") to be held in Mayotte, France, November 15-18, 2018.

--- I was a **visiting professor at the University of West Georgia**, GA, April 23-25, 2018.

-- I was a **visiting professor at the King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, Saudi Arabia**, from November 17, 2017 to January 28, 2018. Among other things, I held a weekly seminar in there and gave talks in the following universities: KFUPM, University of Dammam, and KAUST.

- I was a **Visiting Professor at the University of Abomey-Calavi, Cotonou, Benin, from July 28, 2017 to August 18, 2017**. Among other things, I gave 10 lectures on "Evolution Equations and Their Applications".

--- I was a **Visiting Professor** at **The University of West Georgia, Carrolton, Georgia, USA**, from April 13, 2017 to April 15, 2017.

--- I was a **Visting Professor** at the **King Fahd University of Petroleum and Minerals **(KFUPM),** Dhahran, Saudi Arabia**, from December 9, 2016 to January 9, 2017. Among other things, I gave several lectures, participacited in two workshops, and gave talks in other Saudi universities in Riyadh and Jeddah.

--- I was a Visiting Lecturer **at the African Institute of Mathematical Sciences in Senegal** from November 14, 2016 to November 19, 2016. Among other things, I gave 8 lectures on "Almost Periodic Functions and Their Applications to PDEs".

--- I organized a **Conference in honor of Prof. Mahouton Norbert Hounkonnou** on his 60th Birthday. The conference was held in Cotonou, Benin, 29-30 October 2016.

--- I participated (as an external examiner) in the **PhD Defense of Mr. Tongobe Mounkoro** that took place on May 13, 2016 at the Faculte des Sciences de Bamako, Mali.

--- I was a **visitng professor** at the **Faculte des Sciences de Bamako, Mali**, from May 5, 2016 to May 13, 2016.

--- I was a **visiting professor** at the **King Fahd University of Petroleum & Minerals (KFUPM), Dhahran, Saudi Arabia**, from December 11, 2015 to December 21, 2015.

---- I participated (as an external examiner) in the **PhD Defense** **of Abdelkarim Nidal Akdad** that took place on November 24, 2015 at the University Cadi Ayyad, Marrakech, Morocco.

--- I was a **visiting professor** at the **University of Cadi Ayyad, Marrakech, Morocco**, from November 22, 2015 to November 28, 2015.

--- T. Diagana (with F. Ramaroson) Non-Archimedean Operator Theory. Springer, New York, 2015. (**NEW BOOK**).

--- I visited the "**Mathematical Sciences Research Institute**" (MSRI) in Berkeley, California, from August 24, 2015 to August 29, 2015.

--- I was a **Visiting Professor** at the **University of Chile, Santiago**, from July 23, 2015 to August 1, 2015.

--- I was a **Visiting Professor** at the **Université Paris 1 - Panthéon-Sorbonne, France** from March 14, 2015 to March 23, 2015.

--- I participated (as an external examiner) in the **PhD defense** **of Mamadou Moustapha Mbaye** that took place at the Université Gaston Berger, Saint-Louis, Senegal, on January 26, 2015.

--- I attended the "**13th International Conference on p-Adic Functional Analysis**" held in Paderborn, Germany, from 08/12/2014 to 08/16/2014.

**RESEARCH INTERESTS**

I am interested in the stability, the existence and uniqueness of (periodic, almost periodic, almost automorphic, pseudo-almost periodic, pseudo-almost automorphic) solutions to degenerate differential equations, fractional differential equations, difference equations, integro-differential equations, and stochastic differential equations as well as their applications to practical problems. I am also interested in a general spectral theory for unbounded linear operator in the non-archimedean setting.

In addition to the above-mentioned research activities, I also serve as the Editor-in-Chief and/or the Managing Editor of the following mathematical journals: Nonautonomous Dynamical Systems (de Gruyter), Communications in Mathematical Analysis (Mathematical Research Publishers), and Journal of Abstract Differential Equations and Applications (Mathematical Research Publishers) and serve in the editorial boards of several other mathematical journals.

**SELECTED PUBLICATIONS (2013-2018)**

The fulltexts (in pdf) of some of my papers can be downloaded through the website of **ResearchGate**: Toka Diagana's ResearchGate Website

- T. Diagana (with D. Pennequin) Almost Periodic Solutions for Some Semilinear Singular Difference Equations. Journal of Difference Equations and Applications. Vol. 24 (2018), Issue 1, pp. 138-147.
- T. Diagana, Spectral Analysis for Infinite Rank Perturbations of Unbounded Diagonal Operators. P-adic Numbers, Ultrametric Analysis and Applications. Vol.
**9**(2017), no. 2, pp. 242-246. - T. Diagana, Well-posedness for Some Damped Elastic Systems in Banach Spaces. Applied Mathematics Letters Vol.
**71**(2017), pp. 74-80. - T. Diagana (with S. Araci, M. Acikgoz, and H. M. Srivastava) A novel Approach for Obtaining New Identities for the Lambda Extension of q-Euler Polynomials Arising from q-Umbral Calculus. The Journal of Nonlinear Science and Applications Vol.
**10**(2017), no. 4, p. 1316-1325. - T. Diagana (with H. Maiga) Some New Identities and Congruences for Fubini Numbers. Journal of Number Theory Vol.
**173**(2017), p. 547-569. - T. Diagana, Existence Results for Some Nonautonomous Integro-Differential Equations. Journal of Convex and Nonlinear Analysis. Vol.
**17**(2016), no. 8, pp. 1465--1483. - T. Diagana (with F. Ramaroson) Non-Archimedean Operator Theory. Springer, New York, 2016. (
**NEW BOOK**) - T. Diagana (with F. Ramaroson) Spectral Theory for Finite Rank Perturbations of Unbounded Diagonal Operators in Non-Archimedean Hilbert Space. To Appear in “Contemporary Matematics (American Mathematical Society) --- 2015.
- T. Diagana (with M. M. Mbaye) Leslie-Gower Competition Model with Survival Rate in an Almost Automorphic Environment. To Appear in "International Journal of Difference Equations" --- 2015.
- T. Diagana (with Aymen Ammar and Aref Jeribi) Perturbations of Fredholm Linear Relations in Banach Spaces with Application to 3x3 Block Matrices of Linear Relations. Arab Journal of Mathematical Sciences (in press) --- 2015.
- T. Diagana, Perturbations of Unbounded Fredholm Linear Operators in Banach Spaces. Handbook in Operator Theory, Springer, pp. 1--5, 2014.
- T. Diagana, Existence Results for Some Higher-Order Evolution Equations with Time-Dependent Unbounded Operator Coefficients. Math. Slovaca
**65**(2015), no. 1, 121--140. - T. Diagana (K. Ezzinbi and M. Miraoui), Pseudo-almost periodic and pseudo-almost automorphic solutions to some evolution equations involving theoretical measure theory. Cubo: A Mathematical Journal
**16**(2014), no. 2, 1--31. - T. Diagana (with R. Kerby, T. H. Miabey, and F. Ramaroson),Spectral analysis for finite rank perturbations of diagonal operators in non-archimedean Hilbert space. p-Adic Numbers Ultrametric Anal. Appl.
**6**(2014), no. 3, 171—187. - T. Diagana, Almost Automorphic Solutions to a Beverton-Holt Dynamic Equation with Survival Rate. Applied Mathematics Letters, Vol.
**36**(2014), pp. 19-24. - T. Diagana, Existence Results for Some Damped Second-Order Volterra Integro-differential Equations. Applied Mathematics and Computation Vol.
**237**(2014), pp. 304-317. - T. Diagana (with S. Abbas and M. Benchohra), Existence and Attractivity Results for Fractional Order Partial Integrodifferential Equations with Delay. Afr. Diaspora J. Math. Vol.
**15**(2013), no. 2, pp. 87-100. - T. Diagana, Existence of Pseudo-Almost Automorphic Mild Solutions to Some Nonautonomous Second-Order Differential Equations. Rocky Mountain Journal of Mathematics. Vol.
**43**(2013), no. 3, pp. 793--824. - (
**NEW BOOK**) T. Diagana,*Almost Automorphic Type and Almost Periodic Type Functions in Abstract Spaces*.**Springer**, 2013, New York, 303 pages. - T. Diagana, Existence of Globally Attracting Almost Automorphic Solutions to Some Nonautonomous Higher-Order Difference Equations. Applied Mathematics and Computations
**219**(2013), 6510-6519. - T. Diagana (with M. Arienmughare) Existence of Almost Periodic Solutions to Some Singular Differential Equations. Nonlinear Dynamics and Systems Theory. Vol.
**13**(2013), no. 1, pp. 1-12. - T. Diagana (with M. Zitane), Stepanov-Like Pseudo-Almost Automorphic Functions in Lebesgue Spaces with Variable Exponents L
^{p(x) . }Electronic Journal of Differential Equations. Vol.**2013**(2013), no. 188, pp. 1-20. - T. Diagana, Erratum to: Almost Automorphic Mild Solutions to Some Classes of Nonautonomous Higher-Order Differential Equations. Semigroup Forum
**87**(2013), no. 1, pp. 275-276. - T. Diagana, Bounded Solutions to Some Classes of Nonautonomous Higher-Order Differential Equations. Afrik. Mat.
**24**(2013), no. 1, pp. 33-53.