The coincidence problem and the Swampland conjectures in the Ijjas-Steinhardt cyclic model of the universe

The coincidence problem and the Swampland conjectures in the Ijjas-Steinhardt cyclic model of the universe

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In the Ijjas-Steinhardt cyclic model, the universe passes through phases dominated by radiation, matter, and a dark energy scalar field, with the value of the scale factor increasing with each cycle.Since each cycle terminates in a finite time, it is straightforward to calculate the fraction of time click here that the universe spends in a state for which the matter and dark energy densities have comparable magnitudes; when this fraction is large, it can be taken as a solution of the coincidence problem.This solution of the coincidence problem requires a relatively short lifetime for each cycle, but unlike in the case of phantom models, there is no turbosound ts-18sw700/8a fixed upper bound on this lifetime.However, scalar field models satisfying the Swampland conjectures yield sufficiently short lifetimes to provide a satisfactory resolution of the coincidence problem.