Researchers foresee the existence of three new long-term gravitational signature signatures as part of a unified mathematical framework to identify such effects.
Gravitational waves created by colliding black holes and other extreme cosmic phenomena are transient in nature. However, researchers predicted in the 1970s that passing waves could leave permanent traces of detectors. Recent improvements of the LIGO and Virgo gravitational wave sensors significantly improved their sensitivity, creating a new interest in these predictive effects. For this reason, Eana Flanagan of Cornell University, New York, and colleagues have improved the mathematical framework used to describe the so-called permanent gravitational waves that predict three new observations in the process.
The framework, developed by the team, links possible measurable effects with spatial time curvature by collisions of black holes. Gravitational waves disturb the shape of space-time, altering the relative positions, velocities, accelerations and trajectories of physical objects in their paths. These objects do not return to their original configurations after the waves pass, creating a "permanent" effect that scientists could measure. One example of a measurable constant change is the projected displacement of the relative positions of the LIGO mirrors. The team framework takes into account early predicted persistent observations, including an example of a LIGO mirror, in a mathematical formulation and provides three new ones. These new effects include displacement of time measurements through clocks at different locations and variations in rotational speed of a rotating particle.
The small number of black hole collisions so far discovered by LIGO and Virgo is insufficient to provide the cumulative data needed to detect permanent gravitational waves. But the increased detection frequency expected from modernized detectors may change this situation. However, the discovery of the three newly discovered observers will require new types of observatories.
This study was published in Physical Review D,
– Matthew R. Francis
Matthew R. Francis is a freelance physicist and writer based in Cleveland, Ohio.