Born October 3, 1928; Married 1964, 4 children

BSc University of Athens 1950

PhD University of Athens 1953

Professor of Astronomy University of Thessaloniki 1957-1975.

Professor of Astronomy University of Athens 1975-1996.

Emeritus Professor of Astronomy University of Athens 1996-now.

Academician, Academy of Athens, 1997-now.
President of the Academy of Athens, 2012

Visiting Professor:

Yale University, 1962; Harvard University, 1968; MIT, 1969; Cornell University, 1982; University of Chicago, 1969, 1981; University of Maryland, 1971, 1974, 1978; University of Florida, 1985, 1986, 1987, 1990, 1991, 1993, 1994; University of Milano, 1988, 1992; Florida State University 1998.

Research Associate:

Yerkes Observatory, 1963; Institute for Advanced Study, Princeton, 1963; Institute for Space Studies, 1963,1965,1966,1967; Goddard Space Flight Center, NASA, 1971; Columbia University, 1968; European Southern Observatory, 1976, 1977, 1979, 1980, 1982, 1983, 1984, 1985, 1986, 1987, 1988.

Scientific Work:

He published over 270 papers on Galactic Dynamics, Relativity and Celestial Mechanics and 3 books in English: (1) Cosmology (with D. Kotsakis) Springer Verlag 1987. (2) Order and Chaos in Dynamical Astronomy, Springer Verlag 2002, reprinted 2004. (3) Adventures in Order and Chaos, Kluwer 2004. He was also editor of 11 Proceedings Volumes (6 published by the International Astronomical Union, and 3 by Springer Verlag) and author of 4 textbooks on Astronomy in Greek.
There are over 5.500 citations to his work, and over 320 acknowledgements, in papers of various authors.
He published also about 200 short papers, abstracts, reports, etc

Lectures-Meetings:

He gave over 550 invited lectures at various Μeetings or Institutes in many countries.

Theses Supervised: about 50

Teaching:

He has given courses in General Astronomy, Astrophysics, Dynamical Astronomy, Cosmology, Celestial Mechanics, Galactic Dynamics, Nonlinear Systems, Quantum Mechanics, Plasma Physics, Probability and Statistics, and General Mathematics.

Positions held:

Distinctions:

Key Publications

• A Third Integral of Motion in a Galaxy: 1960, Z.Astrophys. 49, 273.
• A Classification of the Integrals of Motion: 1963, Astrophys.J. 138,1297.
• The "Third" Integral in the Restricted Three-Body Problem: 1965, Astrophys.J. 142, 802.
• Orbits in Highly Perturbed Dynamical Systems. I. Stability of Periodic Orbits: 1970, Astron.J. 75, 96.
• Resonance Effects in Spiral Galaxies: 1970, Astrophys.J. 160, 113.
• On the Number of Isolating Integrals in Hamiltonian Systems: 1978, Phys. Rev. A 18, 1183 (with L. Giorgilli and A. Galgani).
• Orbits in Barred Galaxies: 1989, Astron.Astrophys. Review 1, 261 (with P. Grosbol).
• Periodic Orbits and Chaos around Two Fixed Black Holes: 1990, Proc. Roy. Soc. A 431, 183.
• Invariant Spectra of Orbits in Dynamical Systems: 1994, J.Phys. A 27, 4899 (with N. Voglis).
• Stickiness and Cantori: 1997, J. Phys.A 30, 8167 (with C. Efthymiopoulos, N. Voglis and R. Dvorak).
• Chaos in Bohmian Quantum Mechanics: 2006, J. Phys. A, 39, 1819 (with C. Efthymiopoulos).