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Singularities in Inflationary Cosmology: A Review

Arvind Borde·Alexander Vilenkin
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Abstract

We review here some recent results that show that inflationary cosmological models must contain initial singularities. We also present a new singularity theorem. The question of the initial singularity re-emerges in inflationary cosmology because inflation is known to be generically future-eternal. It is natural to ask, therefore, if inflationary models can be continued into the infinite past in a non-singular way. The results that we discuss show that the answer to the question is ``no.'' This means that we cannot use inflation as a way of avoiding the question of the birth of the Universe. We also argue that our new theorem suggests - in a sense that we explain in the paper - that the Universe cannot be infinitely old.

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Arvind Borde, Alexander Vilenkin. 1996-12-15. Singularities in Inflationary Cosmology: A Review. https://doi.org/10.1142/s0218271896000497

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