# On the Davies-Unruh effect in a wide range of temperatures

## TL;DR

This paper explores how modifications to the Davies-Unruh effect within Entropic Gravity Theory at low temperatures could emulate dark matter and explain galactic phenomena, linking thermodynamics, quantum effects, and gravity.

## Contribution

It introduces a temperature-dependent modification to the Davies-Unruh effect in EGT, connecting it to dark matter emulation and galactic dynamics.

## Key findings

- At low temperatures, EGT requires a modified Davies-Unruh effect.
- The modified effect can emulate dark matter effects in galaxies.
- EGT predicts galaxy cluster mass-temperature relations near the Debye temperature.

## Abstract

The Debye model of the specific heat of solid at low temperatures is incorporate in the Entropic Gravity Theory (EGT). Rather of a smooth surface, the holographic screen is considered as an oscillating elastic membrane, with a continuous range of frequencies, that cuts off at a maximum (Debye) temperature, $T_D$. We show that at low temperatures $T < T_D$, the conservation of the equivalence principle in EGT requires a modification of the Davies-Unruh effect. While the maintenance of Davies-Unruh effect requires a violation of the equivalence principle. These two possibilities are equivalents, because both can emulate the same quantity of dark matter. However, in both cases, the central mechanism is the Davies-Unruh effect, this seems to indicate that the modification of the Davies-Unruh effect emulates dark matter which in turn can be see as a violation of the equivalence principle. This scenario is promising to explain why MOND theory works at very low temperatures (accelerations) regime, i. e., the galaxies sector. We also show that in the intermediate region, for temperatures slightly lower or slightly higher than Debye temperature, EGT predicts the mass-temperature relation of hot X-ray galaxy clusters.