Probing Dark Matter Using Precision Measurements of Stellar Accelerations

Area of Science:

• Astronomy and Astrophysics
• Cosmology
• Particle Physics

Background:

• Dark matter constitutes the majority of the Universe's matter, yet its fundamental nature and origin are unknown.
• Understanding the Milky Way's dark matter distribution is vital for cosmology and for guiding dark matter particle detection experiments.
• Current methods for estimating Galactic dark matter rely on indirect inferences from stellar velocity distributions, incorporating model-dependent assumptions.

Purpose of the Study:

• To introduce a novel method for directly probing the local gravitational potential of the Milky Way.
• To measure the dark matter density distribution and profile morphology in our Galaxy.
• To provide a new observational strategy for dark matter searches.

Main Methods:

• Applying the precision radial velocity method, refined for exoplanet detection, to measure stellar velocity changes over time.
• Utilizing numerical simulations to devise a strategy for observing differential stellar accelerations with next-generation telescopes.
• Achieving a measurement sensitivity of 10^{-8} cm/s² for stellar accelerations.

Main Results:

• Demonstrated a realistic observational strategy for detecting minute stellar accelerations.
• Quantified the requirement for reducing stellar noise in radial velocity measurements to below 10 cm/s for 10³ stars.
• Showcased the potential to extract local dark matter density and profile parameters from measured accelerations.

Conclusions:

• The proposed precision radial velocity method offers a direct observational probe of the Galactic gravitational potential.
• This technique can significantly advance our understanding of dark matter distribution within the Milky Way.
• The findings pave the way for more precise dark matter searches and cosmological model validation.