Scalars Gliding through an Expanding Universe

Area of Science:

• Cosmology
• Particle Physics
• Theoretical Physics

Background:

• Massive bosonic fields are crucial in various cosmological models.
• Understanding their dynamics is key to explaining phenomena like dark matter and inflation.
• Hubble expansion typically causes friction, leading to dilution of field energy.

Purpose of the Study:

• To investigate the impact of single derivative mixing on massive bosonic fields.
• To explore how this mixing affects field dynamics, oscillations, and friction.
• To demonstrate potential applications in particle physics and cosmology.

Main Methods:

• Theoretical analysis of massive bosonic fields with single derivative mixing.
• Examination of the regime of large mixing.
• Illustrative examples including axionlike particles, QCD axions, and scalar field inflation.

Main Results:

• Large mixing delays classical oscillations of bosonic fields.
• Derivative mixing decreases or eliminates friction from Hubble expansion.
• Parametric enhancement of axionlike particle abundance is shown.
• QCD axion abundance can be enhanced, supporting misalignment-driven dark matter.
• Delayed oscillations can sustain cosmic inflation.
• Frictionless scalar field evolution and non-diluting energy are demonstrated.

Conclusions:

• Single derivative mixing offers a novel mechanism to modify bosonic field behavior.
• This phenomenon has significant implications for dark matter, inflation, and early universe cosmology.
• The findings open new avenues for exploring fundamental physics with scalar fields.