Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Natural Emergence of LCDM Cosmology within General Relativity from Two Alternative Frameworks Without Fine-Tuning and Coincidence

H. R. Fazlollahi

Abstract

In this study, by revisiting the quantum interpretation of the cosmological constant, we introduce its formal representation within standard General Relativity. Examining its behavior in a Friedmann-Robertson-Walker spacetime reveals a mechanism in which the symmetry between energy and momentum is dynamically broken. Applying this concept naturally leads to the derivation of the familiar LCDM model, while simultaneously alleviating both the fine-tuning and coincidence problems. Comparison of the ground-state energy behavior in the Friedmann equations with a dust matter field further indicates that large-scale matter exhibits the same symmetry-breaking behavior. Remarkably, due to this broken symmetry, the interactions between local regions of matter in the large-scale structure generate effective pressure, driving late-time acceleration and reproducing the LCDM expansion history without invoking exotic fields or negative-pressure components. This framework provides a self-consistent realization of LCDM within General Relativity, emerging entirely from the intrinsic dynamics of standard matter without fine-tuning and coincidence problems.

Natural Emergence of LCDM Cosmology within General Relativity from Two Alternative Frameworks Without Fine-Tuning and Coincidence

Abstract

In this study, by revisiting the quantum interpretation of the cosmological constant, we introduce its formal representation within standard General Relativity. Examining its behavior in a Friedmann-Robertson-Walker spacetime reveals a mechanism in which the symmetry between energy and momentum is dynamically broken. Applying this concept naturally leads to the derivation of the familiar LCDM model, while simultaneously alleviating both the fine-tuning and coincidence problems. Comparison of the ground-state energy behavior in the Friedmann equations with a dust matter field further indicates that large-scale matter exhibits the same symmetry-breaking behavior. Remarkably, due to this broken symmetry, the interactions between local regions of matter in the large-scale structure generate effective pressure, driving late-time acceleration and reproducing the LCDM expansion history without invoking exotic fields or negative-pressure components. This framework provides a self-consistent realization of LCDM within General Relativity, emerging entirely from the intrinsic dynamics of standard matter without fine-tuning and coincidence problems.
Paper Structure (6 sections, 62 equations, 2 figures, 1 table)

This paper contains 6 sections, 62 equations, 2 figures, 1 table.

Table of Contents

  1. Introduction
  2. Ground-State Energy in the $\Lambda$ Paradigm
  3. Energy–Momentum Symmetry and Its Breaking in Gravitational Dynamics
  4. Dynamical $\Lambda$ from Symmetry Breaking
  5. Cosmos Without a Dark Energy Sector
  6. Concluding Remarks and Implications

Figures (2)

  • Figure 1: Marginalized posterior distributions and confidence regions for the parameter set $\{H_0, z_T, \gamma\}$ from the MCMC analysis of the Pantheon+SH0ES dataset.
  • Figure 2: Redshift evolution of the total equation-of-state parameter $\omega_{\rm tot}$ (top) and deceleration parameter $q$ (bottom) compared with the $\Lambda$CDM model.