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The Cosmological Constant Problems (Talk given at Dark Matter 2000, February, 2000)

Steven Weinberg
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Abstract

The old cosmological constant problem is to understand why the vacuum energy is so small; the new problem is to understand why it is comparable to the present mass density. Several approaches to these problems are reviewed. Quintessence does not help with either; anthropic considerations offer a possibility of solving both. In theories with a scalar field that takes random initial values, the anthropic principle may apply to the cosmological constant, but probably to nothing else.

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Steven Weinberg. 2000-05-12. The Cosmological Constant Problems (Talk given at Dark Matter 2000, February, 2000). https://arxiv.org/abs/astro-ph/0005265

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