Holographic dark energy cosmology, also known as entropic cosmology, provides a concrete physical understanding of the late accelerated expansion of the universe. The acceleration appears to be a consequence of entropy associated with information storage in the universe. Therefore, the assumption of an ad-hoc dark energy is not necessary. In this paper, we investigate the implications of a multicomponent model (radiation and non-relativistic matter) that includes a subdominant power-law term within a thermodynamically admissible model. We use a generic power-law entropy and the temperature of the universe horizon results from the requirement that the Legendre structure of thermodynamics is preserved. We analyse the behaviour for different combinations of the parameters and compare them with other cosmological models, the observed redshift dependencies of the Hubble parameter $H$ and the luminosity distance data obtained from supernovae. This is an early attempt to analyse a multicomponent holographic dark energy model. Furthermore, the analysis is based on a entropy scaling with an arbitrary power of the Hubble radius instead of a specific entropy. This allows us to simultaneously infer different models, compare them and conserve the scaling exponent as a parameter that can be fitted with the observational data, thus providing information about the form of the actual cosmological entropy and temperature. We show that the introduced correction term is able to explain different acceleration and deceleration periods in the late-time universe by solving the model numerically. We discuss the advantages and disadvantages of holographic dark energy models compared to mainstream cosmology.

Holographic dark energy cosmology, also known as entropic cosmology, is a theory that provides a concrete physical understanding of the late accelerated expansion of the universe without the need for an ad-hoc dark energy. Instead, it attributes the acceleration to entropy associated with information storage in the universe. In this paper, we present an investigation of a specific multicomponent model that includes radiation and non-relativistic matter, as well as a subdominant power-law term within a thermodynamically admissible framework.

We start by using a generic power-law entropy and derive the temperature of the universe horizon based on the requirement that the Legendre structure of thermodynamics is preserved. By analyzing different combinations of parameters, we compare our model with other cosmological models and also consider the observed redshift dependencies of the Hubble parameter $H$ and the luminosity distance data from supernovae.

This study represents an early attempt to analyze a multicomponent holographic dark energy model and expands upon previous research by introducing an entropy scaling with an arbitrary power of the Hubble radius instead of a specific entropy. This approach allows for the inference and comparison of different models while conserving the scaling exponent as a parameter that can be fitted with observational data, providing insights into the actual cosmological entropy and temperature.

Using numerical simulations, we demonstrate that our model with the introduced correction term is capable of explaining various acceleration and deceleration periods in the late-time universe. We also discuss the advantages and disadvantages of holographic dark energy models compared to mainstream cosmology.

Future Roadmap

Challenges

  • Refinement of Model: Further refinement and exploration of the multicomponent holographic dark energy model is necessary to better understand its implications and test its predictions against a wider range of observational data.
  • Data Constraints: Obtaining accurate and precise observational data, particularly measurements of the Hubble parameter and luminosity distance, will be crucial in validating or refining holographic dark energy models.
  • Theoretical Development: A deeper understanding of the underlying physics and theoretical framework of holographic dark energy cosmology is needed to fully grasp its implications and potential limitations.

Opportunities

  • Exploring New Parameterizations: Further exploration of different parameterizations and scaling exponents can lead to new insights into the nature of cosmological entropy and temperature.
  • Comparison with Alternative Models: Comparing holographic dark energy models with alternative cosmological models can help assess their relative strengths and weaknesses, potentially leading to a better understanding of the universe’s expansion.
  • Applications to Fundamental Physics: The study of holographic dark energy and its connection to entropy and information storage in the universe opens up possibilities for understanding fundamental physics and potentially uncovering new laws and principles.

Conclusion

The study of holographic dark energy cosmology presents an alternative framework for explaining the late accelerated expansion of the universe without resorting to dark energy. This paper contributes to the field by investigating a specific multicomponent model and analyzing its behavior in comparison with other cosmological models and observational data. While challenges remain in refining the model and obtaining accurate data, opportunities for further exploration and theoretical development are abundant. The potential applications of holographic dark energy in understanding fundamental physics make it an exciting area for future research.

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