AST-763intermediate

The Cosmological Constant: Physical Mechanisms

The cosmological constant, written Λ, is the simplest dark-energy term in Einstein's equations. The cosmological constant provides the baseline model for expansion forecasts, cosmic distances, structure growth, and tests for evolving dark energy.

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The Cosmological Constant: Physical Mechanisms

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AST-762The Cosmological Constant: Structures & Vocabulary→

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AST-764The Cosmological Constant: Observation, Measurement & Evidence→

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The cosmological constant, written Λ, is the simplest dark-energy term in Einstein's equations.

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A constant vacuum-like energy density has negative pressure in general relativity.

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A constant-Λ model fits a wide combination of CMB, supernova, BAO, and large-scale-structure data remarkably well.