Comparing the Motion of Dark Matter and Standard Model Particles on Cosmological Scales
Dark matter, still undetected directly, remains mysterious in its interactions and behavior. The study examines how dark matter moves compared with ordinary matter on cosmological scales and explores the possibility of an additional fifth force acting in the universe.
Methodology and Approach
The researchers test the prevailing assumption that dark matter interacts only through gravity, following Euler’s equation for motion. They achieve this by combining galaxy velocity data with gravitational potential measurements, which are captured through the Weyl potential.
Key Findings
- The observations align with Euler’s equation across redshifts from z = 0.3 to 0.8.
- A positive fifth force, if it exists, cannot surpass 7% of gravitational strength.
- A negative fifth force is limited to 21% of gravitational strength.
Future Prospects
Upcoming surveys, including the Legacy Survey of Space and Time at the Vera C. Rubin Observatory and the Dark Energy Spectroscopic Instrument, are expected to strengthen these limits, potentially lowering uncertainty to around 2%.
“Current data are consistent with Euler’s equation, suggesting no measurable deviation from gravitational-only interaction for dark matter within the tested redshifts.”
Author’s Summary
This research refines the understanding of dark matter dynamics, tightening limits on any non-gravitational forces and paving the way for more precise cosmological measurements.