An Etymological Dictionary of Astronomy and Astrophysics

1. Physics: A → potential that satisfies both → Poisson’s equation and the → boundary conditions pertinent to a particular field is the only possible potential.
   

2. Math.: If two → continuous functions φ(t) and ψ(t) have one and the same → Laplace transform F(p), then these functions are identically equal.
   

3. Astro.: A → black hole can only be characterized by its → mass, → electric charge, and → angular momentum. See also → no hair theorem.

See also: → uniqueness; → theorem.