GEORGE P FLESSAS
Professor
E-MAIL : gfle@aegean.gr
UNDERGRADUATE STUDIES
Technical University of Vienna, Austria (Diplom Ingenieur), 1971
POSTGRADUATE STUDIES
Technical University of Vienna (Dr. techn. in Mathematical Physics), 1974
PROFESSIONAL HISTORY
 Professor, Department of Information and Communication Systems
Engineering, University of the Aegean (1.02.02-)
 Professor, Department of Mathematics, University of the Aegean (1.10.8831.01.02)
 Visiting Professor, Department of Applied Mathematics and Physics, School
of Engineering, University of Patras, Greece (1985-1990).
 Research Fellow, Department of Natural Philosophy, University of Glasgow,
Scotland (1978-1985).
PROFESSIONAL SOCIETIES/INTERNATIONAL COMMITTEES
 Institute of Physics (IOP), Great Britain
EDITORIAL BOARDS (REFEREE)
 Journal of Physics A : Mathematical and General,
 Journal of Mathematical Physics
 Physics Letters A
 Journal of Mathematical Analysis and Applications
RESEARCH INTERESTS
 Ordinary Differential Equations and Dynamical Systems
 Analytic Solutions and Asymptotic Analysis
 Group – Theoretical Approach to Ordinary Differential Equations
RESEARCH COLLABORATIONS
 Professor P G L Leach, Department of Mathematics and Applied Mathematics,
University of Durban, Republic of South Africa
FUNDING OF RESEARCH GRANTS
 ΓΓΕΤ (General Secretariat for Research and Technology)
PAPERS
Journal publications
1. Nuclear rotation for low and high spin values: G. P. Flessas, Zeitschrift fur
Physik, A 279 (1976) 187.
2. On an analytical angular momentum projection method: G. P. Flessas, Lettere al
Nuovo Cimento 19 (1977) 534.
3. On the quantization of the Liouville equation: C. Syros and G. P. Flessas, Lettere
al Nuovo Cimento 20 (1977) 534.
4. On the eigenvalues of the rotating harmonic oscillator: G. P. Flessas, Physics
Letters 71 A (1979) 315.
5. Exact solutions for a doubly anharmonic oscillator: G. P. Flessas, Physics Letters
72 A (1979) 289
6. An exact solution of the Hartree - Fock - Bogolyobov equations: G. P. Flessas,
Lettere al Nuovo Cimento 26 (1979) 492
7. On the three - dimensional anharmonic oscillator: G. P. Flessas and K. P. Das,
Physics Letters 78 A (1980) 19.
8. On the origin of constant matrix elements of a two - body operator: G. P. Flessas,
Lettere al Nuovo Cimento 29 (1980) 82.
9. Exact solutions for a doubly anharmonic oscillator (II): G. P. Flessas, Physics
Letters 81 A (1981) 17.
10. On the Schroedinger equation for the x2 + λx2/(1+Gx2) interaction: G. P. Flessas,
Physics Letters 83 A (1981) 121.
11. Exact solutions for anharmonic oscillators: G. P. Flessas, Journal of Physics A:
Mathematical and General (IOP Journal) 14 (1981) L 209.
12. On the rotating harmonic oscillator equation: G. P. Flessas, Nuovo Cimento 64 B
(1981) 358.
13. An exact solution of the Schroedinger equation for a multiterm poterntial: G. P.
Flessas and A. Watt, Journal of Physics A: Mathematical and General (IOP
Journal) 14 (1981) L 315.
14. Comments on a paper concerning the analytic continued fraction technique for
bound states: G. P. Flessas, Journal of Physics A: Mathematical and General (IOP
Journal) 15 (1982) L 1.
15. Definite integrals as solutions for the x2 + λx2/(1+Gx2) interaction: G. P. Flessas,
Journal of Physics A: Mathematical and General (IOP Journal) 15 (1982) L 97.
16. On the generalized power moment method problem: G. P. Flessas, W. K. Burton
and R. R. Whitehead, Physics Letters 87 A (1982) 201 .
17. Exact solutions for the Schroedinger equation y"(x) + (E - x2 - λx2/(1+Gx2))
y"(x) = 0: R. R. Whitehead, A. Watt, G. P. Flessas and M. A. Nagarajan, Journal
of Physics A: Mathematical and General (IOP Journal) 15 (1982) 1217.
18. On the moment problem for non-positive distributions: G. P. Flessas, W. K.
Burton and R. R. Whitehead, Journal of Physics A: Mathematical and General
(IOP Journal) 15 (1982) 3119.
19. On the applicability of the Hill determinant and the analytic continued fraction
method to anharmonic oscillators: G. P. Flessas and G. S. Anagnostatos, Journal
of Physics A: Mathematical and General (IOP Journal) 15 (1082) L 437.
20. On the ax2 + bx4 interaction: G. P. Flessas, R. R. Whitehead and A. Rigas,
Journal of Physics A: Mathematical and General (IOP Journal) 16 (1983) 85
21. Non-perturbative results for the ax2 + bx4 interaction: G. P. Flessas, Physics
Letters 95 A (1983) 361.
22. Analytic treatment of the ax2 + bx4 oscillator: G. P. Flessas and R. R. Whitehead,
Journal of Mathematical Physics 25 (1984) 910.
23. On a field-theoretic non-polynomial interaction: G. P. Flessas, Physics Letters
100 A (1984) 383.
24. An analysis of the Lorenz equations: stable exact solutions: G. P. Flessas, Physics
Letters 108 A (1985) 4.
25. New exact solutioins of the complex Lorenz equations: G. P. Flessas, Journal of
Physics A: Mathematical and General (IOP Journal) 22 (1989) L 137.
26. A Rodrigues' formula approach to determining closed form solutions to the
Schroedinger equation for symmetric anharmonic oscillators: P. G. L. Leach, G.
P. Flessas and V. M. Gorringe, Journal of Mathematical Physics 30 (1989) 406.
27. A completely integrable case in the complex Lorenz equations: G. P. Flessas and
P. G. Leach, Physics Letters 154 A (1991) 127.
28. Stability of FRW cosmology in higher order gravity: S.Cotsakis and G. P.
Flessas, Physical Review D48 (1993) 3577
29. Generalized cosmic no-hair theorem: S. Cotsakis and G. P. Flessas, Physics
Letters 319B (1993) 69
30. a) Comment on a paper concerning symmetries of equations of motion and
equivalent Lagrangians: G. P. Flessas, P. G. L. Leach and S. Cotsakis, Can. J.
Physics 74 (1994) 86 b) On Noether’s formulation of her theore: G. P. Flessas, P.
G. L. Leach and C. Cotsakis, Can. J. Physics 74 (1995) 543
31. Minimally coupled scalar field wormholes: S. Cotsakis, P. G. L. Leach and G. P.
Flessas, Physical Review D49 (1994) 6489
32. Past-instability conjecture and cosmological attractors in generalized isotropic
universes: S. Cotsakis and G. P. Flessas, Physical Review D51(1995) 4160
33. Graviton creation and conformal non-invariance in higher order gravity theories:
S.Cotsakis and G. P. Flessas, Physical Review D 52(1995) 5783
34. Characterization of the algebraic properties of first integrals of scalar ordinary
differential equations of maximal symmetry: G. P. Flessas, K. S. Govinder and P.
G. L. Leach, Journal of Mathematical Analysis and Applications 212(1997)349374
35. Symmetry, Singularities and Integrability in Complex Dynamics I: The reduction
problem: P G L Leach, S Cotsakis and G P Flessas, Journal of Nonlinear
Mathematical Physics 7(2000) 445
36. Symmetry, Singularities and Integrability in Complex Dynamics II: Rescaling and
time-translation: P G L Leach, S Cotsakis and G P Flessas, Journal of
Mathematical Analysis and Applications 251(2000) 587
37. Ever-expanding, isotropizing, quadratic cosmologies: S. Cotsakis, G. P. Flessas,
P. G. L. Leach and L. Querella, Gravitation and Cosmology 6(2000) 1
38. Solutions in closed form and as power series to the real Lorenz equations: P. G.
L. Leach and G. P. Flessas, Journal of Physics A: Mathematical and General (IOP
Journal) 34 (2001) 6013
39. Complete symmetry groups of ordinary differential equations and their integrals :
some basic considerations: K Andriopoulos, P G L Leach and G P Flessas, Journal
of Mathematical Analysis and Applications 262(2001) 256
40. Generalisations of the Laplace – Runge – Lenz vector: P G L Leach and G P
Flessas, Journal of Nonlinear Mathematical Physics 10(2003) 340.
41. Stochastic effects of the non-linear Schroedinger equation: G P Flessas, P G L
Leach and A N Yannacopoulos, Journal of Optics B: Quantum and Semiclassical
Optics (IOP Journal) 6 (2004) 161
42. Nonlinear ordinary differential equations: Symmetries and singularities, G P
Flessas and P G L Leach, Problems of nonlinear analysis in Engineering Systems
No. 1(22), vol. 11, 2005.
43. Riemann's equation and Lie point symmetries: G P Flessas, P G L Leach, Phys.
Scr. (IOP Journal) 73 (2006) 377.
44. Noetherian first integrals : P G L Leach and G P Flessas, Journal of Nonlinear
Mathematical Physics 5(2008)9
International recognition
I) Citations (up to 16/06/2014): Over 771 by third parties in 462 publications (see list
below).
a) Excluding also self-citations by co-authors over 643 in 381 publications.
b) Excluding all other co-authors over 605 in 373 publications.
II) In the title of the paper : Pursey D L, Journal of Mathematical Physics 31 (9)
(1990) 2170, where paper 26 above is cited, new polynomials in the mathematical
bibliography are introduced under the name “ The Leach – Flessas – Gorringe
Polynomials “
Citations as can be seen from the international database SCISEARCH (equivalent to
ISI).
NO
C=
S=
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
HITS
SEARCH EXPRESSION
36910717
IS74
10
RF="FLESSAS G,1982,V15,PL 97"
6
RF=FLESSAS G,1982,V15,PL 97
5
RF=FLESSAS G,1982,V15,PL97
7
RF=FLESSAS GP,,V,P
1
RF=FLESSAS GP,,V14,PL 315
1
RF=FLESSAS GP,1973,V,P
1
RF=FLESSAS GP,1976,V 279,P 187
4
RF=FLESSAS GP,1979,V27,P289
14
RF=FLESSAS GP,1979,V71,P315
76
RF=FLESSAS GP,1979,V72,P289
79
RF=FLESSAS GP,1980,V78,P19
1
RF=FLESSAS GP,1980,V78,PA 19
1
RF=FLESSAS GP,1981,V14,P209
10
RF=FLESSAS GP,1981,V14,PL 209
5
RF=FLESSAS GP,1981,V14,PL 315
22
RF=FLESSAS GP,1981,V14,PL209
14
RF=FLESSAS GP,1981,V14,PL315
4
RF=FLESSAS GP,1981,V64,P358
42
RF=FLESSAS GP,1981,V81,P17
1
RF=FLESSAS GP,1981,V83,P103
83
RF=FLESSAS GP,1981,V83,P121
1
RF=FLESSAS GP,1981,V84,P121
1
RF=FLESSAS GP,1981,V87,P201
2
RF=FLESSAS GP,1982,V15,P3119
4
RF="FLESSAS GP,1982,V15,PL 1"
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
W?;WHITEHEAD
83
84
W?;WHITEHEAD R?)
14
4
7
4
2
12
3
1
19
8
1
9
4
1
3
1
2
1
10
1
1
8
1
2
1
11
6
1
1
1
1
1
73
1
1
1
19
7
1
13
6
4
1
1
21
5
2
2
30
1
22
0
71
19
1
73
2
RF="FLESSAS GP,1982,V15,PL 1"
RF=FLESSAS GP,1982,V15,PL 537
RF=FLESSAS GP,1982,V15,PL 97
RF=FLESSAS GP,1982,V15,PL1
RF=FLESSAS GP,1982,V15,PL437
RF=FLESSAS GP,1982,V15,PL537
RF=FLESSAS GP,1982,V15,PL97
RF=FLESSAS GP,1982,V87,P201
RF=FLESSAS GP,1983,V16,P85
RF=FLESSAS GP,1983,V95,P361
RF=FLESSAS GP,1984,V,P
RF=FLESSAS GP,1984,V100,P383
RF=FLESSAS GP,1984,V25,P910
RF=FLESSAS GP,1984,V25,P923
RF=FLESSAS GP,1985,V108,P4
RF=FLESSAS GP,1988,V,P
RF=FLESSAS GP,1988,V,P161
RF=FLESSAS GP,1989,V22,PL 137
RF=FLESSAS GP,1991,V154,P127
RF=FLESSAS GP,1992,V15,P121
RF=FLESSAS GP,1994,V,P
RF=FLESSAS GP,1994,V36,P63
RF=FLESSAS GP,1994,V72,P
RF=FLESSAS GP,1994,V72,P86
RF=FLESSAS GP,1995,V,P
RF=FLESSAS GP,1997,V212,P349
RF=FLESSAS GP,2004,V6,PS161
RF=FLESSAS JP,1984,V25,P923
RF=FLESSAS P,1980,V78,P19
RF=FLOSSES GP,1983,V95,P361
RF=SYROS C,1977,V20,P213
RF=WHITEHEAD RR,1982,V15,P
RF=WHITEHEAD RR,1982,V15,P1217
RF=WHITEHEAD RR,1982,V15,P1227
RF=WHITEHEAD RR,1982,V15,P217
RF=LEACH PGL,1989,V30,P1525
RF=LEACH PGL,1989,V30,P406
RF=COTSAKIS S,1993,V48,P3577
RF=COTSAKIS S,1993,V,P
RF=COTSAKIS S,1993,V319,P69
RF=COTSAKIS S,1994,V49,P6489
RF=COTSAKIS S,1995,V51,P4160
RF=COTSAKIS S,1995,V52,P5783
RF=LEACH PGL,2000,V7,P1
RF=LEACH PGL,2000,V7,P445
RF=LEACH PGL,2000,V251,P587
RF=COTSAKIS S,2000,V6,P291
RF=COTSAKIS S,2000,V6,P66
RF=ANDRIOPOULOS K,2001,V262,P256
RF=ANDRIOPOULOS K,2000,V262,P256
RF=LEACH PGL,2003,V10,P340
58 NOT AU=(SYROS C?;FLESSAS G?)
(12;13;56) NOT AU=(FLESSAS G?;DAS KP)
(6;16;18) NOT AU=(FLESSAS G?;WATT A?)
(24;34) NOT AU=(FLESSAS G?;BURTON
R?)
(59;60;61;62) NOT AU=(WHITEHEAD R?;WATT
A?;FLESSAS G?;NAGARAJAN M?)
25 NOT AU=(FLESSAS G?;BURTON
85
G?;ANAGNOSTATOS G?)
86
A?)
87
88
G?;GORRINGE
17
(28;31;32) NOT AU=(FLESSAS
18
35 NOT AU=(FLESSAS G?;WHITEHEAD R?;RIGAS
5
18
(39;40) NOT AU=(FLESSAS G?;WHITEHEAD R?)
(63;64) NOT AU=(LEACH P?;FLESSAS
7
4
8
1
V?)
45 NOT AU=(FLESSAS G?;LEACH P?)
(65;66) NOT AU=(COTSAKIS S?;FLESSAS G?)
67 NOT AU=(COTSAKIS S?;FLESSAS G?)
(49;50) NOT AU=(FLESSAS G?;LEACH
1
1
3
S?)
69 NOT AU=(COTSAKIS S?;FLESSAS G?)
70 NOT AU=(COTSAKIS S?;FLESSAS G?)
52 NOT AU=(FLESSAS G?;GOVINDER K?;LEACH
2
(71;72) NOT AU=(LEACH P?;COTSAKIS
97
2
G?)
73 NOT AU=(LEACH P?;COTSAKIS S?;FLESSAS
98
G?;LEACH
4
(74;75) NOT AU=(COTSAKIS S?;FLESSAS
99
4
89
90
91
92
P?;COTSAKIS
93
94
95
P?)
96
S?;FLESSAS
G?)
100
101
P?;YANNACOPOULOS
21
6
P?;QUERELLA L?)
(76;77) NOT AU=(ANDRIOPOULOS K?;LEACH
P?;FLESSAS G?)
78 NOT AU=(LEACH P?;FLESSAS G?)
53 NOT AU=(FLESSAS G?;LEACH
A?)
102
1
55 NOT AU=(FLESSAS G?;WHITEHEAD R?)
103
227
(2;3;4;5;7;8;9;10;11;14;15;17;19;20;21;22;23;2
6;27;29;30;33;36;37;38;41;42;43;44;46;47;48;51
;57) NOT AU=(FLESSAS G?)
104
449
2 TO 78
105
449
REFS WHERE 104
... 750 REFS in 449 Hits
106
370
79 TO 103
107
370
REFS WHERE 106
... 624 REFS in 370 Hits
108
110
105 AND RD>=01.01.05
109
110
REFS WHERE 108
... 144 REFS in 110 Hits
110
82
107 AND RD>=01.01.05
111
82
REFS WHERE 110
... 111 REFS in 82 Hits
112
1
RF=FLESSAS GP,1980,V78,P90
113
0
112 AND AU=FLESSAS ?
114
450
105;112
115
450
REFS WHERE 114
... 751 REFS in 450 Hits
116
228
103;112
117
371
106;112
118
371
REFS WHERE 117
... 625 REFS in 371 Hits
119
88
115 AND AU=(FLESSAS G?;SYROS C?;DAS
KP;WATT
A?;BURTON W?;WHITEHEAD R?;NAGARAJAN
M?;ANAGNOSTATOS G?;RIGAS A?;LEACH
P?;GORRINGE
120
88
121
122
362
362
123
124
59
59
125
126
43
43
127
129
130
131
132
133
134
135
136
137
1
1
3
4
1
1
1
7
455
455
138
139
376
376
140
141
367
367
142
143
53
53
144
145
42
42
146
147
148
149
2
1
457
457
150
151
377
377
152
153
368
368
154
155
28
28
156
157
22
22
158
159
160
161
1
1
458
458
V?;COTSAKIS S?;GOVINGER K?;QUERELLA
L?;ANDRIOPOULOS K?;YANNACOPOULOS A?)
REFS WHERE 119
... 165 REFS in 88 Hits
115 NOT 120
REFS WHERE 121
... 586 REFS in 362 Hits
115 AND RD>=12.06.08
REFS WHERE 123
... 76 REFS in 59 Hits
118 AND RD>=12.06.08
REFS WHERE 125
... 56 REFS in 43 Hits
RF=FLESSAS C,1982,V15,PL97
RF=FIESSAS GP,1981,V83,P121
RF=FLEASES GP,1979,V72,P289
RF=FLEASES GP,1980,V78,P19
RF=FLEASES GP,1981,V14,P315
RF=FLEASES GP,1981,V83,P121
RF=FLEASES GP,1982,V15,PL97
127 TO 134
135;115
REFS WHERE 136
... 763 REFS in 455 Hits
118;127 TO 134
REFS WHERE 138
... 637 REFS in 376 Hits
137 NOT 120
REFS WHERE 140
... 598 REFS in 367 Hits
137 AND RD>=01.06.09
REFS WHERE 142
... 72 REFS in 53 Hits
139 AND RD>=01.06.09
REFS WHERE 144
... 57 REFS in 42 Hits
RF=LEACH PGL,2008,V15,P9
146 NOT AU=(LEACH PGL?;FLESSAS G?)
137;146
REFS WHERE 148
... 765 REFS in 457 Hits
139;147
REFS WHERE 150
... 638 REFS in 377 Hits
141;147
REFS WHERE 152
... 599 REFS in 368 Hits
149 AND RD>=17.10.11
REFS WHERE 154
... 38 REFS in 28 Hits
151 AND RD>=17.10.11
REFS WHERE 156
... 30 REFS in 22 Hits
RF=LEACH PGL,2001,V34,P6013
158 NOT AU=(LEACH PGL?;FLESSAS G?)
149;158
REFS WHERE 160
... 766 REFS in 458 Hits
162
163
21
21
164
165
16
16
166
167
168
169
170
171
172
173
1
1
1
1
1
2
462
462
174
175
176
177
1
1
1
1
178
179
180
181
1
1
381
381
161 AND RD>=19.11.12
REFS WHERE 162
... 26 REFS in 21 Hits
151 AND RD>=19.11.12
REFS WHERE 164
... 19 REFS in 16 Hits
RF=FLESSAS GP,1989,V22,PL137
RF=FLESSAS GP,2006,V73,P377
RF=FLEASES FP,1979,V72,P289
RF=COSTAKIS S,1994,V49,P6489
RF=LEARCH P,2004,V10,P340
RF=LEACH PGL,2008,V15,P9
160;166 TO 171
REFS WHERE 172
... 771 REFS in 462 Hits
166 NOT AU=FLESSAS G?
167 NOT (AU=FLESSAS G? OR AU=LEACH P?)
168 NOT AU=FLEASES G?
169 NOT (AU=COTSAKIS S? OR AU=LEACH P?
OR
182
A?;BURTON
89
AU=FLESSAS G?)
170 NOT (AU=LEACH P? OR AU=FLESSAS G?)
171 NOT (AU=LEACH P? OR AU=FLESSAS G?)
151;174 TO 178
REFS WHERE 180
... 643 REFS in 381 Hits
173 AND AU=(FLESSAS G?;SYROS C?;DAS
W?;WHITEHEAD R?;NAGARAJAN
M?;ANAGNOSTATOS
G?;RIGAS A?;LEACH ?;COTSAKIS S?;GOVINGER
K?;QUERELLAS L?;ANDRIKOPOULOS
K?;YANNACOPOULOS
183
89
184
185
373
373
A?)
REFS WHERE 182
... 166 REFS in 89 Hits
173 NOT 183
REFS WHERE 184
... 605 REFS in 373 Hits