Geometric Baryogenesis from Shift Symmetry

Area of Science:

• Cosmology
• Particle Physics
• Theoretical Physics

Background:

• The origin of the Universe's baryon asymmetry remains a key unsolved problem in cosmology.
• Existing models often require complex mechanisms or fine-tuning.
• Nambu-Goldstone (NG) bosons are theoretical particles predicted by spontaneous symmetry breaking.

Purpose of the Study:

• To propose a novel scenario for generating baryon asymmetry in the Universe.
• To explore the role of NG bosons in early Universe cosmology.
• To investigate potential connections between baryogenesis and dark matter candidates.

Main Methods:

• Developing a theoretical framework where NG bosons couple to spacetime geometry and baryons.
• Utilizing shift symmetry to naturally control operators within the theory.
• Analyzing the cosmological background's effect on NG boson dynamics.

Main Results:

• A new mechanism for baryogenesis induced by NG boson motion is presented.
• The QCD axion and axionlike fields are identified as viable candidates for this baryon-generating NG boson.
• The proposed scenario offers a unified explanation for both early Universe baryogenesis and late-Universe dark matter.

Conclusions:

• NG bosons provide a compelling and natural mechanism for generating the observed baryon asymmetry.
• This framework offers a potential link between fundamental particle physics and cosmological observations.
• The QCD axion and similar fields are promising candidates for further investigation in both baryogenesis and dark matter research.