Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter.
In this physical picture the positive dark energy and accelerated expansion are caused by the slow thermalization of the emergent spacetime [28, 29]
- eigenstate thermalization hypothesis (ETH) 1991 Quantum statistical mechanics in a closed system - J. M. Deutsch
Quantum mechanically this means these states violate ETH at short distance and time scales. We believe this can be understood as a manifestation of many-body localization: a quantum analogue of the glass transition known to imply area law entanglement [47, 48]
- 3 Glassy Dynamics and Memory Effects in Emergent Gravity
In this section we address an important conceptual question. How can a theory of emergent gravity lead to observable consequences at astronomical and cosmological scales? We also discuss important features of the microscopic de Sitter states such as their glassy behaviour and occurrence of memory effects. These phenomena play a central role in our derivation of the emergent laws of gravity at large scales.
- 6 The Elastic Phase of Emergent Gravity
We now return to the central idea of this paper. As we explained, the effect of matter is to displace the entropy content of de Sitter space. Our aim is to describe in detail how the resulting elastic back reaction translates into an effective gravitational force. We will describe this response using the standard linear theory of elasticity