Constraining extra dimensions using observations of black hole quasi-normal modes

Area of Science:

• Theoretical physics
• Black hole physics
• Gravitational wave astronomy

Background:

• Rotating black holes possess mass (M) and angular momentum (J).
• Extra dimensions can introduce a 'tidal charge' parameter ($$) modifying spacetime geometry.
• Braneworld scenarios predict extra dimensions manifest as negative $$ values and altered gravitational perturbations.

Purpose of the Study:

• Investigate the impact of the tidal charge parameter on rotating black hole quasi-normal modes.
• Determine quasi-normal mode spectra for braneworld black holes.
• Compare theoretical predictions with gravitational wave data.

Main Methods:

• Numerical solution of perturbed gravitational field equations.
• Continued fractions method for quasi-normal mode determination.
• Analysis of gravitational wave signal GW150914 data.

Main Results:

• Negative tidal charge ($$) values correlate with increased damping times (diminishing imaginary part of quasi-normal modes).
• Consistency checks with GW150914 data suggest unlikely non-zero tidal charge.
• A conservative upper limit on the tidal charge parameter was derived.

Conclusions:

• The study provides constraints on the tidal charge parameter in braneworld black hole models.
• Findings have implications for understanding black hole physics in higher dimensions.
• Future research directions include further observational tests and theoretical refinements.