2023-08-11 11:00  Online

Pulsar Timing Array consortia yield evidence of cosmic gravitational wave background

Prof. Achamveedu Gopakumar

Very recent independent and coordinated investigations by the established Pulsar Timing Array collaborations strongly indicate that the universe is humming with gravitational radiation-a very low-frequency rumble that rhythmically stretches and compresses spacetime and the matter embedded in it. For these IPTA-endorsed 3P+ efforts, the European and Indian Pulsar Timing Array consortia, namely EPTA and InPTA, pooled together their resources that included combining EPTAs second data release and InPTAs first data release. These efforts allowed us to probe and characterize the contributions of instrumental noise and interstellar propagation effects that are present in the various combinations of our pulsar data sets. The resulting detailed investigations reveal strong evidence for the presence of a stochastic gravitational wave background. I will share the excitement of our InPTA collaboration which is an Indo-Japanese effort that employs niche abilities of Indias upgraded Giant Metre wave Radio Telescope (uGMRT). I will also list possible future directions that will benefit a lot from close interactions between us and our colleagues in Taiwan.