115 citations · 744 across the 44 of their papers we have counts for
13 papers · 1 filter
Periodic orbits in a near Yang-Mills potential
George Contopoulos, Mirella Harsoula
We consider the orbits in the Yang-Mills (YM) potential V=1/2 x2 y2 and in the potentials of the general form Vg=1/2 [α (x2 +y2)+x2 y2]. The stable period-9 (number of intersection…
Chaos in 2-d Bohmian Trajectories
Athanasios C. Tzemos, George Contopoulos
We make a short review of the most general mechanism for the generation of chaos in 2-d Bohmian trajectories, the so called `nodal point-X-point complex' (NPXPC) mechanism. The pre…
Precessing ellipses as the building blocks of spiral arms
M. Harsoula, K. Zouloumi, C. Efthymiopoulos +1
Stable periodic orbits in spiral galactic models that form families of precessing ellipses can create spiral density waves similar to those that are observed in real grand-design g…
Manifold spirals in barred galaxies with multiple pattern speeds
C. Efthymiopoulos, M. Harsoula, G. Contopoulos
In the manifold theory of spiral structure in barred galaxies, the usual assumption is that the spirals rotate with the same pattern speed as the bar. Here we generalize the manifo…
Characteristic times in the standard map
Mirella Harsoula, Kostas Karamanos, George Contopoulos
We study and compare three characteristic times of the standard map, the Lyapunov time t_L, the Poincare recurrence time t_r and the stickiness (or escape) time t_{st}. The Lyapuno…
Highlights of chaos research
George Contopoulos
We describe some highlights in the theory of chaos, that started with Poincare (1899). Generic systems have both ordered and chaotic domains. Chaos appears mainly near un- stable p…