Definition

1. Noun:
   • An arbitrary constant in the equations of general relativity theory: A term introduced by Albert Einstein into his field equations of general relativity to allow for a static universe. It represents a uniform energy density (or negative pressure) inherent to space itself, which can cause the universe to expand or contract.

Usage Examples

• Noun:
  • Einstein originally introduced the cosmological constant to achieve a static model of the universe.
  • Modern observations suggest the cosmological constant may be the simplest explanation for dark energy, driving the accelerated expansion of the universe.

Advanced Usage

• "The cosmological constant problem": Refers to the significant discrepancy between the observed small value of the cosmological constant and the much larger value predicted by quantum field theory.
  • The cosmological constant problem remains one of the greatest unsolved mysteries in theoretical physics.

Variants and Related Words

• Lambda (Λ): The Greek letter commonly used as the symbol for the cosmological constant in equations.
  • In the Friedmann equations, Lambda represents the cosmological constant term.

Synonyms

• Vacuum energy: A concept in quantum mechanics often conceptually linked to the cosmological constant, representing the energy of empty space.
• Dark energy: In modern cosmology, the cosmological constant is the leading candidate model for the dark energy causing cosmic acceleration.

Related Phrases

• "Cosmological constant term": The specific component in an equation representing this constant.
  • The cosmological constant term in Einstein's equation can be moved to the right-hand side and interpreted as a fluid with negative pressure.

Noun

1. an arbitrary constant in the equations of general relativity theory