Implication of Pulsar Timing Array Experiments on Cosmological Gravitational Wave Detection

Understand

Gravitational waves provide a new probe of the Universe which can reveal a number of cosmological and astrophysical phenomena that cannot be observed by electromagnetic waves.

• Different frequencies of gravitational waves are detected by different means.
• Among them, precision measurements of pulsar timing provides a natural detector for gravitational waves with light-year scale wavelengths.
• In this review, first a basic framework to detect a stochastic gravitational wave background using pulsar timing array is introduced, and then possible interpretations of the latest observational result of 12.5 year NANOGrav data are described.