Scalar Relics from the Hot Big Bang

Area of Science:

• Cosmology
• Particle Physics

Background:

• The nature of dark matter remains one of the most significant unsolved problems in modern physics.
• The Standard Model of particle physics does not account for dark matter, necessitating extensions or new physics.

Purpose of the Study:

• To investigate if scalar fields with specific coupling strengths can naturally explain the observed cosmological dark matter abundance.
• To explore the mass range and coupling properties of such scalar fields.

Main Methods:

• Theoretical modeling of scalar field dynamics and their interactions with Standard Model particles.
• Analysis of cosmological dark matter abundance predictions based on scalar field couplings.

Main Results:

• Scalar field couplings, approximately 10^{-6}(m_{ϕ}/eV)^{-1/4} relative to gravity, can account for the total dark matter abundance.
• This explanation is valid for a broad scalar field mass range from 10^{-12} to 10^{14} eV.
• The results are robust, showing minimal sensitivity to the specific Standard Model particles (electrons, photons, hadrons) the scalar field couples to.

Conclusions:

• Scalar fields provide a compelling candidate for dark matter that unifies cosmological observations with particle physics.
• The findings establish a direct link between fifth force experiments, probing deviations from gravity, and the ongoing search for dark matter particles.