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arXiv · 2601.05628

Entanglement Entropy and Complexity of Multicomponent Universe from Holography

Abstract

Recent studies in \cite{Park:2020jio,Paul:2025gpk} have calculated various holographic information-theoretic quantities of the four-dimensional FLRW universe for different matter-dominated eras using the braneworld model of cosmology. These studies are done for a single matter component, which is a good toy model for understanding the entanglement properties of the universe. However, for a more realistic model, one should consider a scenario where our universe has coexisting matter components like radiation-dark matter or radiation-exotic matter, etc. In this work, we have presented a systematic way to study various holographic information-theoretic quantities, namely, entanglement entropy and complexity, of the FLRW universe in the presence of coexisting matter components. We have shown that the black brane geometry in the presence of $p$-brane gas indeed supports the existence of a universe with two-component matter sources. The second Israel junction condition, along with the Ryu-Takayanagi formula, is used to compute the time-dependent holographic entanglement entropy of the universe with coexisting radiation-dark matter and radiation-exotic matter. The expression of the time-dependent volume complexity is also evaluated in these scenarios. For both universes, these information-theoretic quantities show a clear radiation dependence in the early time and matter and exotic matter dominance in the late time, which is consistent with the thermal history of the universe \cite{WMAP:2010qai,WMAP:2010sfg,Planck:2014loa,Planck:2018vyg}.

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BibTeXRIS

Ritam Mahanta, Gopinath Guin, Souvik Paul, Sunandan Gangopadhyay. 2026-07-28. Entanglement Entropy and Complexity of Multicomponent Universe from Holography. https://doi.org/10.1093/ptep%2Fptag115

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