Dynamical Constraints on the Cosmological Parameters

TL;DR

This paper derives constraints on the cosmic curvature and cosmological constant, suggesting a spherical universe and providing bounds relevant for dark matter and dark energy research.

Contribution

It presents new theoretical constraints on cosmological parameters based on assumptions about the universe's initial singularity and cyclic models.

Findings

Universe likely has positive curvature ($K=1$) as a 3-sphere.

Cosmological constant $\Lambda$ is constrained to be less than approximately $10^{-24} { m ly}^{-2}$.

Constraints aid understanding of dark matter and dark energy properties.

Abstract

In cosmology, the cosmic curvature $K$ and the cosmological constant $\Lambda$ are two important parameters, and the values have strong influence on the behavior of the universe. In the context of normal cosmology, under the ordinary assumptions of positive mass-energy and initial negative pressure, we find the initial singularity of the universe is certainly absent and we have $K=1$. This means total spatial structure of the universe should be a 3-dimensional sphere $S^3$. For the cyclic cosmological model, we have $\Lambda\lesssim 10^{-24} {\rm ly}^{-2}$. Obviously, such constraints would be helpful for the researches on the properties of dark matter and dark energy in cosmology.