The Observable Universe in a Simplified Cosmic Dynamic Model

Xiaoyun Li,Youping Dai,Suoang Longzhou,Yangsheng Xu,La Ba Sakya Genzon

doi:10.4236/jamp.2021.96089

Abstract

This paper introduces a cosmic expansion model with constant speed of cosmic spatial expansion via derivation and simulations, where the speed of cosmic spatial expansion equals the speed of light c. Simulation results show that the earliest observable universe time is t = 5.084 Gyrs where the current universe time T = 13.82 Gyrs, and the furthest observable distance at the earliest observable universe time t is S = 0.632R, where R is the cosmic radius at current universe time T. The above constant cosmic expansion model does not consider the inflation period in the early universe according to the Big Bang model, nor does it considered the cosmic acceleration in recent universe time. However, this simplified cosmic expansion model could be a benchmark that will be helpful to understand the cosmic expansion and the observable universe. Based on the derivation and simulation of the constant cosmic expansion model, the threshold of observable universe for the accelerated cosmic expansion model can also be calculated similarly, as far as the speed of cosmic spatial expansion at any universe time t can be provided.

Highlights

Introduction and Related WorksThe measurement of the distance of stars and galaxies in the universe has always been one of the main research topics of cosmology
This paper introduces a cosmic expansion model with constant speed of cosmic spatial expansion via derivation and simulations, where the speed of cosmic spatial expansion equals the speed of light c
Simulation results show that the earliest observable universe time is t = 5.084 Gyrs where the current universe time T = 13.82 Gyrs, and the furthest observable distance at the earliest observable universe time t is S = 0.632R, where R is the cosmic radius at current universe time T

Summary

Introduction and Related Works

The measurement of the distance of stars and galaxies in the universe has always been one of the main research topics of cosmology. While in the Big Band model [6], the speed of cosmic spatial expansion is much faster than the speed of light c during the inflation period in the early universe. The main contribution of this paper is that the simplified constant cosmic expansion model introduces cosmic expansion dynamics, which shows that after a light source such as a galaxy omitted a beam of light to the Earth when the beam of light was travelling in the universe before arriving the Earth, the cosmic space was expanding at the same time. The distance between the light source and the Earth can be obtained Based on this model, the earliest observable universe time can be derived.

Constant Cosmic Expansion Model

Deriving the Threshold of Observable Universe

Accelerated Cosmic Expansion Model

Conclusions