# Isotropic cosmological singularities 1: Polytropic perfect fluid spacetimes

Source: [Isotropic cosmological singularities 1: Polytropic perfect fluid spacetimes](<https://www.sota2.com/research/paper/68fa24d32c2a3760193a9685>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-24T09:34:09.845Z

Authors: K. Anguige, K. P. Tod

Published: 1999-03-02T10:35:18.000Z

## Abstract

We consider the conformal Einstein equations for polytropic perfect fluid cosmologies which admit an isotropic singularity. For the polytropic index gamma strictly greater than 1 and less than or equal to 2 it is shown that the Cauchy problem for these equations is well-posed, that is to say that solutions exist, are unique and depend smoothly on the data, with data consisting of simply the 3-metric of the singularity. The analogous result for gamma=1 (dust) is obtained when Bianchi type symmetry is assumed.

## Recorded benchmark results

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## Original sources and implementation

[Original paper](<https://arxiv.org/abs/gr-qc/9903008>)

[PDF](<https://arxiv.org/pdf/gr-qc/9903008.pdf>)