James Okoye Chukuka Ezeilo

Born:

place: Nigeria

B.Sc. London University (1953); M.Sc. London University (1955)

Ph.D. University
of Cambridge (Queen's College - 1959).

thesis: *Some Topics in the Theory of Ordinary Non-linear differential
Equations of the Third Order*

Department of Mathematics;
University of Swaziland; Kwaluseni, Swaziland

email: EZEILO@science.uniswa.sz

Also see the web page: Who are the
greatest Black Mathematicians?

James Ezeilo took his B.Sc. of London University in 1953 with First Class Hons and the M.Sc. ( also of London University) in 1955, received his Ph.D. from University of Cambridge (Queens' College) in 1958.

Professor James Ezeilo, with **Chike
Obi** and **Adegoke Olubummo**,
was one of a trio of black mathematicians who **pioneered**
modern mathematics
research in Nigeria is sometimes called the "father of
mathematics" in Nigeria. Dr. James Ezeilo's early research
dealt mainly with the problem of stability, boundedness, and convergence
of solutions of third order ordinary differential equations. Apart
from extending known results and techniques to higher order equations,
the main thrust of his work was the construction of Lyapunov-like
functions, which he did elegantly and used to study the qualative
properties of solutions. In addition he was a pioneer in the use
of Leray-Schauder degree type arguments to obtain existence results
for periodic solutions of ordinary differential equations.

James Okoye Chukuka Ezeilo received the degrees of DSc *honoris
causa* from the University of Maiduguri, 1989-11-, and the
University of Nigeria, Nsukka, 1996-04-, and the degree of DTech
*honoris causa* from the Federal University of Technology,
Akure, 1995-11-.

Special issue in honour of Professor James O. C. Ezeilo: **J. Nigerian Math.
Soc.** {**11**} (1992), no. 3. **Nigerian
Mathematical Society**, University of Ibadan, Department
of Mathematics, Ibadan, 1992. pp. i--iv and 1--146.

Adichie, J. N. __Professor J. O. C. Ezeilo: More than three
decades of active academic work__. Special issue in honour of
Professor James O. C. Ezeilo. **J.
Nigerian Math. Soc.** **11** (1992), no. 3, i--iv.

Selected Research

70. **Ezeilo, J.O.C.** __Non-resonant oscillations for
some third order differential equations II__, **J.
Nigerian Math. Soc.** 8 (1989), 25-48 (with J.O.C.)

69. **Ezeilo, J. O. C.**; Nkashama, M. N. __Resonant and
nonresonant oscillations for some third order nonlinear ordinary
differential equations__. Nonlinear Anal. **12** (1988),
no. 10, 1029--1046.

68. **Ezeilo, J. O. C.**; Onyia, J. __Nonresonant oscillations
for some third-order differential equations__. **J.
Nigerian Math. Soc.** **3** (1984), 83--96 (1986).

67. **Ezeilo, J. O. C.** __An application of a theorem
of Güssefeldt in the proof of the existence of periodic solutions
of a certain class of differential equations__. **J.
Nigerian Math. Soc.** **2** (1983), 79--89.

66. **Ezeilo, J. O. C.** __Uniqueness theorems for periodic
solutions of certain fourth and fifth order differential systems__.
**J. Nigerian
Math. Soc.** **2** (1983), 55--59.

65. **Ezeilo, J. O. C.** __Some properties of the differential
equation $f(u)=d\sp{p}u/dt\sp{p}$\ of arbitrary order $p\geq 1$__.
Qualitative theory of differential equations, Vol. I, II (Szeged,
1979), pp. 231--241, Colloq. Math. Soc. János Bolyai, **30**,
North-Holland, Amsterdam-New York, 1981.

64. **Ezeilo, J. O. C.** __Periodic solutions of certain
sixth order differential equations__. J. Nigerian Math. Soc.
**1** (1982), 1--9.

63. **Ezeilo, J. O. C**. __A Leray\mhy Schauder technique
for the investigation of periodic solutions of the equation $\ddot
x+x+µ x\sp{2}=\varepsilon \,{\rm cos}\,\omega t$ $(\varepsilon
\not=0)$__. Acta Math. Acad. Sci. Hungar. **39** (1982),
no. 1-3, 59--63.

62. **Ezeilo, J. O. C.** __Existence of periodic solutions
of a certain system of fifth-order differential equations__.
Ninth international conference on nonlinear oscillations, Vol.
1 (Kiev, 1981), 420--422, 454, "Naukova Dumka", Kiev,
1984. 34C25

61. **Ezeilo, James O. C.** __On the existence of periodic
solutions of certain third order nondissipative differential systems__.
Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur. (8) **66**
(1979), no. 2, 126--135. 34C25

60. **Ezeilo, James O. C**. __Extension of certain instability
theorems for some fourth and fifth order differential equations__.
Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur. (8) **66**
(1979), no. 4, 239--242. 34D05 (34A30)

59. **Ezeilo, James O. C.** __A further result on the existence
of periodic solutions of the equation $\dotiii x+\psi (\dot x)\ddot
x+\varphi (x)\dot x+\theta (t,\,x,\,\dot x,\,\ddot x)=p(t)$ with
a bounded $\theta $__. Atti Accad. Naz. Lincei Rend. Cl. Sci.
Fis. Mat. Natur. (8) **65** (1978), no. 1-2, 51--57 (1979).
34C25

58. **Ezeilo, James O. C.** __Periodic solutions of certain
third order differential equations of the nondissipative type__.
Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur. (8) **63**
(1977), no. 3-4, 212--224 (1978).

57. **Ezeilo, James O. C.** __Periodic solutions of a certain
fourth order differential equation__. Atti Accad. Naz. Lincei
Rend. Cl. Sci. Fis. Mat. Natur. (8) **63** (1977), no. 3-4,
204--211 (1978).

56. **Ezeilo, J. O. C.** __An instability theorem for a
certain sixth order differential equation__. J. Austral. Math.
Soc. Ser. A **32** (1982), no. 1, 129--133.

55. **Ezeilo, James O. C.**; **T\d
ejum\d ola, Haroon O.** __Periodic solutions of a certain
fourth order differential equation__. Atti Accad. Naz. Lincei
Rend. Cl. Sci. Fis. Mat. Natur. (8) **66** (1979), no. 5, 344--350.

54. **Ezeilo, James O. C.** *Further results on the existence
of periodic solutions of a certain third order differential equation
*. Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur.
(8) **63** (1977), no. 6, 493--503 (1978).

53. **Ezeilo, James O. C.** Further results on the existence
of periodic solutions of a certain third-order differential equation.
Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur. (8) **64**
(1978), no. 1, 48--58.

52. **Ezeilo, J. O. C.** A further instability theorem for
a certain fifth-order differential equation. Math. Proc. Cambridge
Philos. Soc. **86** (1979), no. 3, 491--493.

51. **Ezeilo, J. O. C.** *Instability theorems for certain
fifth-order differential equations *. Math. Proc. Cambridge
Philos. Soc. **84** (1978), no. 2, 343--350.

50. **Ezeilo, J. O. C.** *An instability theorem for a
certain fourth order differential equation *. Bull. London
Math. Soc. **10** (1978), no. 2, 184--185.

49. **Ezeilo, J. O. C.**; **Tejumola,
H. O.** *Periodic solutions of certain fifth order differential
equations *. Nonlinear vibration problems, No. 15 (Proc. Sixth
Internat. Conf. Nonlinear Oscillations, Pozna\'n, 1972, Part II),
pp. 75--84. PWN---Polish Sci. Publ., Warsaw, 1974. 34C25

48. **Eseilo, J. O. C**. *New properties of the equation
$x+ax+bx+h(x)=p(t,x,x,x)$ for certain special values of the incrementary
ratio $y\sp{-1}\{h(x+y)-h(x)\}$ *. Équations différentielles
et fonctionnelles non linéaires (Actes Conférence
Internat. "Equa-Diff 73", Brussels/Louvain-la-Neuve,
1973), pp. 447--462. Hermann, Paris, 1973.

47. **Ezeilo, J. O. C.**; **Tejumola,
H. O.** *On the boundedness and the stability properties
of solutions of certain fourth order differential equations *.
Ann. Mat. Pura Appl. (4) **95** (1973), 131--145.

46. **Ezeilo, James O. C.**; **Tejumola,
Haroon O.** *Further remarks on the existence of periodic
solutions of certain fifth order non-linear differential equations
*. Atti. Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur.
(8) **58** (1975), no. 3, 323--327.

45. **Ezeilo, James O. C.**; **Tejumola,
Haroon O.** Further results for a system of third order
differential equations. Atti Accad. Naz. Lincei Rend. Cl. Sci.
Fis. Mat. Natur. (8) **58** (1975), no. 2, 143--151.

44. **Ezeilo, J. O. C**. *Periodic solutions of certain
third order differential equations *. Atti Accad. Naz. Lincei
Rend. Cl. Sci. Fis. Mat. Natur. (8) **57** (1974), no. 1-2,
54--60 (1975).

43. **Ezeilo, James O. C.** *Some new criteria for the
existence of periodic solutions of a certain second order differential
equation *. Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat.
Natur. (8) **56** (1974), no. 5, 675--683.

42. **Ezeilo, James O. C.; Tejumola,
H. O.** *Boundedness theorems for certain third order
differential equations *. Atti Accad. Naz. Lincei Rend. Cl.
Sci. Fis. Mat. Natur. (8) **55** (1973), 194--201 (1974).

41. **Ezeilo, J. O. C.** *A further result on the existence
of periodic solutions of the equation $\dotiii x+a\ddot x+b\dot
x+h(x)=p(t,x,\dot x,\ddot x)$ *. Math. Proc. Cambridge Philos.
Soc. **77** (1975), 547--551.

40. **Ezeilo, James Okoye Chukuka** Periodic solutions of
a certain third order differential equation. Atti Accad. Naz.
Lincei Rend. Cl. Sci. Fis. Mat. Natur. (8) **54** (1973), 34--41.

39. **Ezeilo, J. O. C.** *A generalization of some boundedness
results by Reissig and Tejumola *. J. Math. Anal. Appl. **41**
(1973), 411--419.

38. **Ezeilo, J. O. C.** *A boundedness theorem for a
certain $n$th order differential equation *. Ann. Mat. Pura
Appl. (4) **88** (1971), 135--142.

37. **Ezeilo, J. O. C.** *A boundedness theorem for a
certain fourth order differential equation *. J. London Math.
Soc. (2) **5** (1972), 376--384.

36. **Ezeilo, J. O. C.; Tejumola,
H. O.** *Boundedness theorems for some fourth order differential
equations *. Ann. Mat. Pura Appl. (4) **89** (1971), 259--275.

35. **Ezeilo, J. O. C.; **Tejumola,
H. O. *A boundedness theorem for a certain fourth order
differential equation *. Ann. Mat. Pura Appl. (4) **88 **(1971),
207--216.

34. **Ezeilo, James Okoye Chukuk**a *A generalization
of a boundedness theorem for the equation $\ddot x+\alpha \ddot
x+\phi\sb 2$ $(\ddot x)+\phi\sb 3$ $(x)=\psi (t,x,\dot x,\ddot
x)$ *. Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur.
(8) **50** (1971), 424--431.

33. **Ezeilo, J. O. C.** *A generalization of a theorem
of Reissig for a certain third order different equation *.
Ann. Mat. Pura Appl. (4) **87** (1970), 349--356.

32. **Ezeilo, J. O. C.** *On the boundedness of the solutions
of the equation $\dotiii x+a\ddot x+f(x)\dot x+g(x)=p(t)$ *.
Ann. Mat. Pura Appl. (4) **80** 1968 281--299.

31. Ezeilo, J. O. C. *On the stability of the solutions of
some third order differential equations *. J. London Math.
Soc. **43** 1968 161--167.

30. Ezeilo, J. O. C. *A generalization of a boundedness theorem
for a certain third-order differential equation *. Proc. Cambridge
Philos. Soc. **63** 1967 735--742.

29. Ezeilo, J. O. C. *$n$-dimensional extensions of boundedness
and stability theorems for some third order differential equations
*. J. Math. Anal. Appl. **18** 1967 395--416.

28. Ezeilo, J. O. C. *On the stability of solutions of certain
systems of ordinary differential equations *. Ann. Mat. Pura
Appl. (4) **73** 1966 17--26.

27.Ezeilo, J. O. C.; Tejumola,
H. O. *Boundedness and periodicity of solutions of a certain
system of third-order non-linear differential equations *.
Ann. Mat. Pura Appl. (4) **74** 1966 283--316.

26. Ezeilo, J. O. C. Corrigendum: *A boundedness theorem
for a certain third-order differential equation *. Proc. London
Math. Soc. (3) **17** 1967 382--384.

25. Ezeilo, J. O. C. *A generalization of a result of Demidovi\v
c on the existence of a limiting regime of a system of differential
equations *. Portugal. Math. **24** 1965 65--82.

24. Ezeilo, J. O. C. Erratum: *On the existence of almost
periodic solutions of some dissipative second order differential
equations *. Ann. Mat. Pura Appl. (4) **74** 1966 399.

23. Ezeilo, J. O. C. *A note on the convergence of solutions
of certain second order differential equations *. Portugal.
Math. **24** 1965 49--58.

22. Ezeilo, J. O. C. *A stability result for a certain third
order differential equation *. Ann. Mat. Pura Appl. (4) **72**
1966 1--9.

21. Ezeilo, J. O. C. *On the convergence of solutions of
certain systems of second order differential equations *. Ann.
Mat. Pura Appl. (4) **72** 1966 239--252.

20. Ezeilo, J. O. C. *Some boundedness results for a fourth
order nonlinear differential equation *. 1964 Nonlinear Vibration
Problems, 5, Second Conf. on Nonlinear Vibrations, Warsaw, 1962
pp. 252--257 Pa\'nstwowe Wydawnictwo Naukowe, Warsaw

19. Ezeilo, J. O. C. *An estimate for the solutions of a
certain system of differential equations *. Nigerian J. Sci.
**1** 1966 5--10.

18. Ezeilo, J. O. C. *A stability result for the solutions
of certain third order differential equations *. J. London
Math. Soc. **37** 1962 405--409.

17. Ezeilo, J. O. C. *Stability results for the solutions
of some third and fourth order differential equations *. Ann.
Mat. Pura Appl. (4) **66** 1964 233--249.

16. Ezeilo, J. O. C. *On the existence of an almost periodic
solution of a non-linear system of differential equations *.
Contributions to Differential Equations **3** 1964 337--349.

15. Ezeilo, J. O. C. *On the existence of almost periodic
solutions of some dissipative second order differential equations
*. Ann. Mat. Pura Appl. (4) **65** 1964 389--405.

14. Ezeilo, J. O. C. __A boundedness theorem for some non-linear
differential equations of the third order__. J. London Math.
Soc. **37** 1962 469--474.

13. Ezeilo, J. O. C. __An extension of a property of the phase
space trajectories of a third order differential equation__.
Ann. Mat. Pura Appl. (4) **63** 1963 387--397.

12. Ezeilo, J. O. C. __An elementary proof of a boundedness
theorem for a certain third order differential equation__. J.
London Math. Soc. **38** 1963 11--16.

11. Ezeilo, J. O. C. __A boundedness theorem for a differential
equation of the third order__. 1963 Qualitative methods in the
theory of non-linear vibrations (Proc. Internat. Sympos. Non-linear
Vibrations, Vol. II, 1961) pp. 513--538 Izdat. Akad. Nauk Ukrain.
SSR, Kiev

10. Ezeilo, J. O. C. __Some results for the solutions of a
certain system of differential equations__*.* J. Math.
Anal. Appl. **6** 1963 387--393.

9. Ezeilo, J. O. C. __Further results for the solutions of
a third-order differential equation__. Proc. Cambridge Philos.
Soc. **59** 1963 111--116.

8. **Ezeilo, J. O. C.** __On the boundedness and the stability
of solutions of some differential equations of the fourth order__.
J. Math. Anal. Appl. **5** 1962 136--146.

7. **Ezeilo, J. O. C.** __A boundedness theorem for a certain
third-order differential equation__. Proc. London Math. Soc.
(3) **13** 1963 99--124.

6. **Ezeilo, J. O. C.** __A property of the phase-space
trajectories of a third-order non-linear differential equation__.
J. London Math. Soc. **37** 1962 33--41.

5. **Ezeilo, J. O. C.** __A stability result for solutions
of a certain fourth order differential equation__. J. London
Math. Soc. **37** 1962 28--32.

4. **Ezeilo, J. O. C.** __A note on a boundedness theorem
for some third order differential equations__. J. London Math.
Soc. **36** 1961 439--444.

3. **Ezeilo, J. O. C.** __On the existence of periodic
solutions of a certain third-order differential equation__.
Proc. Cambridge Philos. Soc. **56** 1960 381--389.

2. **Ezeilo, J. O. C.** __On the stability of solutions
of certain differential equations of the third order__. Quart.
J. Math. Oxford Ser. (2) **11** 1960 64--69.

1. **Ezeilo, J. O. C.** __On the boundedness of solutions
of a certain differential equation of the third order__. Proc.
London Math. Soc. (3) **9** (1959) 74--114.

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