Dark Matter from Exponential Growth.

Area of Science:

• Cosmology
• Particle Physics
• Astrophysics

Background:

• The nature of dark matter (DM) remains one of the most significant unsolved problems in modern physics.
• Current models for DM production, such as freeze-in and freeze-out, explore specific scenarios for its origin.
• Understanding the thermal history of the early universe is crucial for deciphering DM production mechanisms.

Purpose of the Study:

• To propose and analyze a novel mechanism for dark matter production from a thermal bath.
• To investigate the exponential growth of dark matter particle density via a specific interaction.
• To explore how this new mechanism expands the parameter space for explaining observed dark matter abundance.

Main Methods:

• Introducing a novel particle interaction: DM particles (χ) transforming thermal bath particles (ψ) into DM pairs (χψ→χχ).
• Analyzing the resulting exponential growth of the dark matter number density from a small initial abundance.
• Comparing this mechanism with established freeze-in and freeze-out production models.

Main Results:

• Demonstrated exponential growth of dark matter number density through the proposed χψ→χχ interaction.
• Showcased that this mechanism complements existing freeze-in and freeze-out production pathways.
• Identified new, accessible parameter space for explaining the observed dark matter abundance.

Conclusions:

• The proposed thermal bath production mechanism offers a new avenue for dark matter research.
• This mechanism provides a viable alternative or complementary explanation for the universe's dark matter content.
• Further investigation into the observational prospects of this novel dark matter production scenario is warranted.