2025-4-18

Title: Galaxy-based gravitational wave observatory and its promises
 
Speaker: Achamveedu Gopakumar (TIFR)
 
Date: April 18 at 14:30
 
Location: R521, General Building II
 
Abstract:
Maturing Pulsar timing arrays monitor millisecond pulsars which can be converted into Einstein clocks to search for perturbations due to gravitational waves at nanohertz frequencies. 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. This stochastic GW signal is consistent with that expected from an ensemble of supermassive black hole binaries, but could also be attributable to more exotic sources. I will describe these efforts from the perspectives of the European and Indian Pulsar Timing Array (EPTA+InPTA) consortia. I will share the excitement of our InPTA collaboration which is an Indo-Japanese effort that employs niche abilities of India's upgraded Giant Metrewave Radio Telescope (uGMRT). Possible near future directions involving nHz GWs from individual SMBH binaries that should be exciting to both astronomers and physicists will be listed.