# The transition of a gravitationally radiating, dissipative fluid, to equilibrium

## TL;DR

This paper demonstrates that a gravitationally radiating, dissipative fluid quickly transitions to equilibrium shortly after radiating ceases, challenging previous beliefs that such a return to static conditions is unlikely.

## Contribution

It shows that considering the physical properties of the source leads to a rapid return to equilibrium, contrary to earlier studies that overlooked these properties.

## Key findings

- System reaches equilibrium within thermal relaxation, adjustment, or hydrostatic timescales.
- Contradicts previous studies suggesting static conditions are unlikely after radiation.
- Highlights importance of source properties in gravitational radiation studies.

## Abstract

We describe the transition of a graviationally radiating, axially and reflection symmetric dissipative fluid, to a non--radiating state. It is shown that very shortly after the end of the radiating regime, at a time scale of the order the thermal relaxation time, the thermal adjustment time and the hydrostatic time (whichever is larger), the system reaches the equilibrium state. This result is at variance with all the studies carried out in the past, on gravitational radiation outside the source, which strongly suggest that after a radiating period, the conditions for a return to a static case, look rather forbidding. As we shall see, the reason for such a discrepancy resides in the fact that some elementary, but essential, physical properties of the source, have been overlooked in these latter studies.