Physics

Gravitation

Dark matter

Dark fluid

Mathematics

Hot dark matter

Scalar field dark matter

Particle physics

Astronomy

Macroeconomics

Inflaton

Economics

Dark energy

Inflation (cosmology)

Geometry

Cosmology

Production (economics)

Astrophysics

Scalar (mathematics)

Physical review. D/Physical review. D.

We consider the direct $s$-channel gravitational production of dark matter during the reheating process. Independent of the identity of the dark matter candidate or its nongravitational interactions, the gravitational process is always present and provides a minimal production mechanism. During reheating, a thermal bath is quickly generated with a maximum temperature ${T}_{\mathrm{max}}$, and the temperature decreases as the inflaton continues to decay until the energy densities of radiation and inflaton oscillations are equal, at ${T}_{\mathrm{RH}}$. During these oscillations, $s$-channel gravitational production of dark matter occurs. We show that the abundance of dark matter (fermionic or scalar) depends primarily on the combination ${T}_{\mathrm{max}}^{4}/{T}_{\mathrm{RH}}{M}_{P}^{3}$. We find that a sufficient density of dark matter can be produced over a wide range of dark matter masses: from 1 GeV to 1 ZeV.

Gravitational production of dark matter during reheating