For Ghosts who are planets unto themselves.

### Definition/Summary:

Lambda

- Upper case Greek Lambda is used to denote Einstein’s cosmological constant
- A non-zero Lambda indicates a non-zero vacuum energy density and causes a long-range repulsive effect which leads to the accelerating expansion of the Universe
- This symbol is used in astrophysics, it represents the likelihood that a small body will encounter a planet or a dwarf planet leading to a deflection of a significant magnitude. An object with a large value of lambda is expected to have cleared its neighborhood, satisfying the current definition of a planet

### Expanded info:

Cosmological constant

- Term in Einstein’s general relativity equations that leads to an acceleration of the expansion of the Universe. Usually denoted by Λ, the capital Greek letter Lambda when expressed with units of inverse length squared, or by Ω
_{Λ}or the lower-case Greek lambda (λ) when normalized to the critical density like Ω