# An Exact Interior Kerr Solution

## TL;DR

This paper introduces a new exact solution for the interior of a rotating star, demonstrating that it satisfies all energy conditions despite negative stresses, and highlighting the role of high viscosity in rotating fluids.

## Contribution

It provides a novel exact interior solution for rotating stars, clarifying the stress-energy tensor interpretation and the physical plausibility of negative stresses.

## Key findings

- Solution satisfies all energy conditions.
- Negative stresses are compatible with physical conditions.
- High viscosity is essential for rotating fluid models.

## Abstract

We present a simple exact solution for the interior of a rotating star. The interpretation of the stress energy tensor as that of a fluid requires the existence of a high viscosity, which is quite expected for a rotating fluid. In spite of the negative stresses, energy conditions are in fact all satisfied.