Indian Pulsar Timing Array

The Indian Pulsar Timing Array (InPTA) is a pulsar timing array (PTA), a selected group of pulsars, and an effort to record the timing of the pulsars' cycles using the Giant Metrewave Radio Telescope (GMRT) near Pune in India, and to compare and analyze their timing histories to detect gravitational waves. It is part of the International Pulsar Timing Array (IPTA) collaboration. The array consists of about twenty-five millisecond pulsars (MSPs).

PTAs as gravitational-wave detectors are sensitive to a different range of frequencies than LIGO's and Virgo's 10-10000 Hz regime: the range for PTAs is microhertz and slower (e.g., nanohertz gravitational waves), the presumed detectable sources being binary SMBHs with orbits in this frequency range.