New Source for QCD Axion Dark Matter Production: Curvature Induced

Area of Science:

• Cosmology
• Particle Physics

Background:

• Dark matter remains one of the biggest mysteries in cosmology.
• Scalar fields play crucial roles in both cosmic inflation and axion models.
• The QCD axion is a compelling dark matter candidate, with experimental searches underway.

Purpose of the Study:

• To propose and analyze a novel mechanism for dark matter generation.
• To apply this mechanism specifically to the QCD axion.
• To explore the implications for dark matter abundance and experimental searches.

Main Methods:

• Investigating dark matter production from scalar field fluctuations.
• Analyzing the role of curvature perturbations and background field dynamics.
• Examining the parameter space relevant for the QCD axion.

Main Results:

• Scalar field fluctuations, driven by specific conditions, can account for the observed dark matter abundance.
• The mechanism is effective across a broad range of axion parameters.
• Potential for observable gravitational-wave signatures was identified.

Conclusions:

• The proposed mechanism offers a viable pathway for generating dark matter, particularly the QCD axion.
• This framework connects early universe cosmology (inflation) with particle physics axion models.
• Further investigation into constraints and gravitational-wave signals is warranted.