Emergent Dark Matter in Late Time Universe on Holographic Screen

TL;DR

This paper proposes a holographic model where dark matter emerges from the stress-energy tensor on a hypersurface in higher-dimensional flat spacetime, offering new insights into late-time universe dynamics and galaxy-scale phenomena.

Contribution

It introduces a holographic framework for emergent dark matter using a de Sitter hypersurface and relates it to traditional cosmological models and emergent gravity theories.

Findings

Derived a relation between dark and baryonic matter energy densities.

Presented a holographic interpretation of dark matter consistent with Lambda CDM.

Connected the model to galaxy rotation curves via the Tully-Fisher relation.

Abstract

We discuss a scenario that the dark matter in late time universe emerges as part of the holographic stress-energy tensor on the hypersurface in higher dimensional flat spacetime. Firstly we construct a toy model with a de Sitter hypersurface as the holographic screen in the flat bulk. After adding the baryonic matter on the screen, we assume that both of the dark matter and dark energy can be described by the Brown-York stress-energy tensor. From the Hamiltonian constraint equation in the flat bulk, we find an interesting relation between the dark matter and baryonic matter's energy density parameters, by comparing with the Lambda cold dark matter parameterization. We further compare this holographic embedding of emergent dark matter with traditional braneworld scenario and present an alternative interpretation as the holographic universe. It can be reduced to our toy constraint in the late time universe, with the new parameterization of the Friedmann equation. We also comment on the possible connection with Verlinde's emergent gravity, where the dark matter is treated as the elastic response of the baryonic matter on the de Sitter spacetime background. We show that from the holographic de Sitter model with elasticity, the Tully-Fisher relation and the dark matter distribution in the galaxy scale can be derived.