Pune: Cosmologist L Sriramkumar said gravitational waves could help scientists understand what happened just fractions of a second after the Big Bang. Speaking at the 32nd Raman Memorial Conference (RMC-2026) held at Savitribai Phule Pune University on Thursday, Sriramkumar said latest observations are opening a new window to study the universe.
Cosmologist L Sriramkumar said gravitational waves could help scientists understand what happened just fractions of a second after the Big Bang. (HT)
SPPU’s two-day national conference titled “100 Years of the Schrödinger Equation and its Timeless Impact” brings together students and researchers to discuss modern developments in physics.
During his lecture on “Unravelling the physics of the early universe through gravitational waves”, Sriramkumar said that scientists for decades relied on the Cosmic Microwave Background (CMB), faint radiation leftover from the Big Bang emitted about 380,000 years after the universe was born, to understand the early universe.
The Big Bang is the scientific theory that the universe began about 13.8 billion years ago from an extremely hot, dense state and has been expanding ever since.
“The CMB is uniform in temperature, but contains very tiny variations and gravity amplified these differences over billions of years, forming galaxies and clusters. Though it tells us about the early universe, it cannot take us all the way back to the beginning,” he said, adding that recent results from Pulsar Timing Array (PTA) experiments can tell us about the early universe.
PTA experiments are large-scale projects that use extremely precise timing of rapidly rotating millisecond pulsars — highly magnetised, rapidly rotating neutron star that emits beams of electromagnetic radiation from its magnetic poles — to detect very low-frequency gravitational waves.
Recent PTA observations suggest the presence of a “stochastic gravitational wave background”, a faint hum of gravitational waves coming from all directions in space. “If confirmed, this could be evidence of gravitational waves produced in the very early universe,” he said.
“Gravitational wave astronomy has grown rapidly since the first direct detection of gravitational waves in 2015.” he said.