# Accretion of rotating fluids onto stationary solutions

## TL;DR

This paper develops general laws for the accretion of rotating perfect fluids onto stationary solutions, revealing new effects in Fermi and Bose fluids near horizons, including growth of chemical potential and possible Bose-Einstein condensation cessation.

## Contribution

It introduces a comprehensive framework for accretion of rotating fluids onto stationary backgrounds, highlighting novel effects in degenerate and non-degenerate quantum fluids near horizons.

## Key findings

- Non-degenerate fluids exhibit unbounded chemical potential growth near horizons.
- Ultra-relativistic Fermi fluids show unbounded enthalpy and Fermi momentum growth.
- Degenerate Bose fluids may experience cessation of Bose-Einstein condensation or temperature drop to zero near horizons.

## Abstract

We consider a general stationary solution and derive the general laws for accretion of rotating perfect fluids. For non-degenerate and degenerate Fermi and Bose fluids we derive new effects that mimic the center-of-mass-energy effect of two colliding particle in the vicinity of horizons. Non-degenerate fluids see their chemical potential grow arbitrarily and ultra-relativistic Fermi fluids see their specific enthalpy and Fermi momentum grow arbitrarily too while the latter vanishes gradually for non-relativistic Fermi fluids. For degenerate Bose fluids two scenarios remain possible as the fluid approaches a horizon: a) The Bose-Einstein condensation ceases or b) the temperature drops gradually down to zero.