FIG 5 - uploaded by John Dupuy
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Evolution is shown for φ 2 potential in a universe with a negative cosmological constant and positive spatial curvature. Plotted here are the holonomy solution (solid line) and the connection solution (dashed line). The initial conditions selected for this solution are V (0) = 10 9 , φ(0) = 10 −7 , ˙ φ(0) = 0.1, m = 1, Λ = −0.01 (all in Planck units).
Source publication
Differences in pressure during expansion and contraction stages in cosmic evolution can result in a hysteresis-like phenomena in non-singular cyclic models sourced with scalar fields. We discuss this phenomena for spatially closed isotropic spacetime in loop quantum cosmology (LQC) for a quadratic and a cosh-like potential, with and without a negat...
Contexts in source publication
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... us first discuss the case of an ever increasing cyclic universe. Fig. 5 quantization in LQC, where initial conditions are set in the contracting phase. We see that after a brief period of contraction, a quantum bounce occurs rather quickly which is followed by a short phase of accelerated expansion (evident by a quick growth in the beginning of each cycle). In this phase the volume of the universe grows by ...
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... a steady increase in the amplitude of the scale factor. Our analysis also reveals some new features. Let us start with discussion of simulation shown in Fig. 12, where we show the solutions for holonomy and connection quantizations for a universe with a steepness parameter of q = 2.0 for potential (22). Comparing to the case of φ 2 potential in Fig. 5, we see some similarities but also some differences. As in the case of φ 2 potential with a negative cosmological constant, the holonomy and connection quantizations lead to solutions which are almost identical. Although, there are no quasi-periodic beats in this particular case of the chosen value of q, the universe undergoes an ...
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... parameter is shown in Fig. 17 for q = 6.0 for the holonomy case. Unlike the case of q = 5.0 we find that the quasi-periodic beats have completely disappeared. Rather the universe undergoes an expansion phase with multiple bounces at ever increasing values of scale factor. This figure has some similarity with the case of φ 2 potential discussed in Fig. 5. For higher values of steepness parameter, we find the beats phenomena to become less regular to occur. We find that the existence of quasi-periodic beats is sensitive to the value of steepness parameters if other initial conditions are not changed. In certain cases evolution has close similarities to the φ 2 potential. And, in some of ...
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... us first discuss the case of an ever increasing cyclic universe. Fig. 5 quantization in LQC, where initial conditions are set in the contracting phase. We see that after a brief period of contraction, a quantum bounce occurs rather quickly which is followed by a short phase of accelerated expansion (evident by a quick growth in the beginning of each cycle). In this phase the volume of the universe grows by ...
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... a steady increase in the amplitude of the scale factor. Our analysis also reveals some new features. Let us start with discussion of simulation shown in Fig. 12, where we show the solutions for holonomy and connection quantizations for a universe with a steepness parameter of q = 2.0 for potential (22). Comparing to the case of φ 2 potential in Fig. 5, we see some similarities but also some differences. As in the case of φ 2 potential with a negative cosmological constant, the holonomy and connection quantizations lead to solutions which are almost identical. Although, there are no quasi-periodic beats in this particular case of the chosen value of q, the universe undergoes an ...
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... parameter is shown in Fig. 17 for q = 6.0 for the holonomy case. Unlike the case of q = 5.0 we find that the quasi-periodic beats have completely disappeared. Rather the universe undergoes an expansion phase with multiple bounces at ever increasing values of scale factor. This figure has some similarity with the case of φ 2 potential discussed in Fig. 5. For higher values of steepness parameter, we find the beats phenomena to become less regular to occur. We find that the existence of quasi-periodic beats is sensitive to the value of steepness parameters if other initial conditions are not changed. In certain cases evolution has close similarities to the φ 2 potential. And, in some of ...
