Observational constraints on the dark energy and dark matter mutual coupling

TL;DR

This paper investigates models of interaction between dark energy and dark matter using multiple observational data sets, finding small positive coupling values that address the coincidence problem and align with thermodynamic laws.

Contribution

It provides a comprehensive statistical analysis of phenomenological dark sector interaction models with diverse observational data, including time-dependent measurements.

Findings

Small positive coupling between dark energy and dark matter is favored.

Compatibility among different data sets supports the interaction models.

Results are consistent with solving the coincidence problem and thermodynamics.

Abstract

We examine different phenomenological interaction models for Dark Energy and Dark Matter by performing statistical joint analysis with observational data arising from the 182 Gold type Ia supernova samples, the shift parameter of the Cosmic Microwave Background given by the three-year Wilkinson Microwave Anisotropy Probe observations, the baryon acoustic oscillation measurement from the Sloan Digital Sky Survey and age estimates of 35 galaxies. Including the time-dependent observable, we add sensitivity of measurement and give complementary results for the fitting. The compatibility among three different data sets seem to imply that the coupling between dark energy and dark matter is a small positive value, which satisfies the requirement to solve the coincidence problem and the second law of thermodynamics, being compatible with previous estimates.