What is the cosmological constant equal to?

The value w = −1.028±0.032, measured by the Planck Collaboration (2018) is consistent with −1, assuming w does not change over cosmic time.

What does the fine-structure constant represent?

The fine-structure constant gives the maximum positive charge of an atomic nucleus that will allow a stable electron-orbit around it within the Bohr model (element feynmanium). For an electron orbiting an atomic nucleus with atomic number Z, mv2r = 14πε0 Ze2r2.

What is the meaning of cosmological constant?

Definition of cosmological constant : a constant term used in the relativistic equations for gravity to represent a repulsive force which may account in part for the rate of expansion of the universe.

What is the relationship between dark energy and Einstein’s cosmological constant?

Einstein’s cosmological constant The cosmological constant was first proposed by Einstein as a mechanism to obtain a solution of the gravitational field equation that would lead to a static universe, effectively using dark energy to balance gravity. Einstein gave the cosmological constant the symbol Λ (capital lambda).

Does the fine-structure constant vary?

The fine structure constant has not changed in time. Earlier results have shown that the fine structure is slightly different along a specific axis of the Universe, called a dipole. Now, the latest result is from a single light source along a specific direction, so it’s not definitive on its own.

Is the cosmological constant real?

A new study confirms that the cosmological constant is the best fit for dark energy, and offers the most precise and accurate estimate yet of its value, researchers said. The finding comes from a measurement of the universe’s geometry that suggests our universe is flat, rather than spherical or curved.

Does the cosmological constant vary?

4 Answers. and it is by definition a constant, so it cannot change.

What is the definition of the cosmological constant in physics?

Physical cosmology. In cosmology, the cosmological constant (usually denoted by the Greek capital letter lambda: Λ) is the energy density of space, or vacuum energy, that arises in Albert Einstein’s field equations of general relativity. It is closely associated to the concepts of dark energy and quintessence.

What is the fine structure constant in physics?

In physics, the fine-structure constant, also known as Sommerfeld’s constant, commonly denoted by α (the Greek letter alpha ), is a fundamental physical constant which quantifies the strength of the electromagnetic interaction between elementary charged particles.

What happens when you add the cosmological constant to Einstein’s equations?

In fact, adding the cosmological constant to Einstein’s equations does not lead to a static universe at equilibrium because the equilibrium is unstable: if the universe expands slightly, then the expansion releases vacuum energy, which causes yet more expansion.

What is the asymptotic value of the fine-structure constant?

Therefore, 1 137.036 is the asymptotic value of the fine-structure constant at zero energy. At higher energies, such as the scale of the Z boson, about 90 GeV, one measures an effective α ≈ 1/127, instead .