2018/08/14 by Yurii Ignat’ev, Ignat'ev, Yurii, A. A. Agathonov +3
Engineering · Physics and Astronomy · #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Material Science and Thermodynamics #Relativity and Gravitational Theory
paper · pdf · doi:10.48550/arxiv.1808.04570
openalex publication_date 2018/08/14 · openalex created_date 2022/10/02 · openalex updated_date 2026/07/28
A detailed comparative qualitative analysis and numerical simulation of\nevolution of the cosmological models based on classical and phantom scalar\nfields with self-action was performed. The phase portraits of the dynamic\nsystems of classical and phantom fields and their projections to the Poincare\nsphere were constructed. It was shown that the phase trajectories of the\ncorresponding dynamic systems can be split by bifurcation trajectories into 2,4\nor 6 different dynamic streams corresponding to different pairwise symmetric\nhistories of the Universe depending on the parameters of the scalar field's\nmodel. The phase space of such systems becomes multiply connected, the ranges\nof negative total effective energy unavailable for motion, getting appear\nthere. In the case when attracting centers are situated inside these ranges,\nthe phase trajectories of the classical scalar field in the infinite future\ntend to limit cycles, winding onto the boundaries of these ranges. The phase\ntrajectories of the scalar field, in turn, get away from the boundaries of\nranges with null effective energy and in the infinite future are wound onto one\nof the symmetrical focuses (centers). Thus, the situations when the Universe,\nin case of classical scalar field, begins its history with the inflation and\nends it up in the Euclidean future, or, in the case of phantom scalar field, in\nopposite, has the Euclidian start and proceeds to inflation mode after\nanomalous burst of the acceleration, both become possible. The potentials of\nscalar fields on the surface of null curvature are distinct from zero and\nthereby define a certain vacuum state.\n