Connecting Cosmic Inflation to Particle Physics with LiteBIRD, CMB-S4, EUCLID, and SKA

Area of Science:

• Cosmology
• Particle Physics
• Astrophysics

Background:

• Cosmic Microwave Background (CMB) experiments provide crucial data for understanding the early universe.
• Cosmic inflation is a theoretical period of exponential expansion in the very early universe.
• The reheating phase after inflation is critical for the evolution of cosmic perturbations.

Purpose of the Study:

• To demonstrate that future CMB experiments can measure the inflaton coupling.
• To establish a connection between cosmic inflation and particle physics.
• To probe the reheating phase after inflation.

Main Methods:

• Development of a simple analytic method to estimate sensitivity to reheating temperature and inflaton coupling.
• Application of the method to future CMB missions like LiteBIRD and CMB-S4.
• Analysis of the impact of reheating on the redshifting of cosmic perturbations.

Main Results:

• Future CMB experiments can achieve the first measurement of the inflaton coupling.
• LiteBIRD and CMB-S4 have the potential to set upper and lower bounds on the inflaton coupling within specific inflationary models.
• Combining CMB data with optical and 21 cm surveys can further improve constraints.

Conclusions:

• Future observations offer a new window into the connection between cosmic inflation and particle physics.
• The study highlights the potential of future cosmological surveys to constrain microphysical parameters of inflation.
• Results provide clues for embedding inflationary models within more fundamental theories of nature.