Quantum Creation of a Schwarzschild-de Sitter Black Hole

Using the Hartle-Hawking no-boundary proposal for the wave function of the universe, we can study the wave function and probability of a single Schwarzschild-de Sitter black hole created at the birth of the universe. The black hole originates from a gravitational instanton with conical singularities. The probability of a black hole creation is the exponential of one quarter of the sum of areas of the black hole and cosmological horizons. One quarter of this sum is the total entropy of the universe.