Recognizing Axionic Dark Matter by Compton and de Broglie Scale Modulation of Pulsar Timing

Area of Science:

• Cosmology and astrophysics
• Particle physics
• String theory

Background:

• The search for dark matter is shifting towards light axionic candidates.
• Axionic dark matter, motivated by string theory, offers explanations for galaxy formation and dwarf galaxy cores.
• Direct detection of axionic dark matter's scalar field oscillations is crucial for confirmation.

Purpose of the Study:

• To investigate the de Broglie interference modulation of dark matter.
• To predict observable signatures of axionic dark matter, specifically in the Galactic center.
• To explore the potential of pulsar timing residuals for detecting axionic dark matter.

Main Methods:

• Solving the coupled Schrödinger-Poisson equation for a Bose-Einstein condensate model of dark matter.
• Simulating the behavior of axionic dark matter in the Galactic center.
• Analyzing the impact of oscillating scalar fields on general relativity and pulsar timing.

Main Results:

• Dark matter is predicted to be fully modulated by de Broglie interference, forming dense soliton cores (≃150 pc) at the Galactic center.
• The oscillating field induces general relativistic time dilation, leading to detectable pulsar timing residuals (≃400 nsec).
• Pairwise Galactocentric signatures in pulsar timing can distinguish axionic dark matter from gravitational wave backgrounds.

Conclusions:

• Axionic dark matter provides a compelling model for dark matter phenomena.
• Pulsar timing residuals near the Galactic center offer a promising avenue for detecting axionic dark matter.
• Future radio surveys near the Galactic center could discover new pulsars for this detection method.