The work of two physicists, Professor Thanu Padmanabhan at IUCAA, Pune and Dr Hamsa Padmanabhan at ETH, Zurich, (Swiss Federal Institute of Technology), connects and answers two fundamental questions about the cosmos. An official release issued on Friday by the Inter University Centre for Astronomy and Astrophysics, said that they have discovered the correct value for the size of the small fluctuations in the early universe, which later led to the creation of larger structures like galaxies. The two scientists, in their forthcoming paper to be published in Physics Letters B, argue that the very existence, as well as the tiny numerical value of the cosmological constant, can be understood as a direct consequence of the information content of cosmic space and time.
There are two tantalising mysteries about our universe — thought to be unconnected with each other — which have intrigued cosmologists for decades. The first one is about the existence of something called ‘dark energy’, which is speeding up the expansion of the universe at present. Current observations suggest that the nature of dark energy can be explained by invoking a term in Albert Einstein’s equations of gravity, called the Cosmological Constant. But, for this idea to work, the cosmological constant should have a very specific — and enormously tiny — value. Explaining this tiny but non-zero number is considered to be the greatest challenge faced by theoretical physics today.
The new element brought in by the authors is the concept of cosmic information, called CosmIn. The two physicists show that the maximum amount of cosmic information accessible to an observer in our universe, will be finite, only if the universe undergoes an accelerated phase of expansion later, exactly as we observe.
Thanu and Hamsa Padmanabhan do not postulate an inflationary phase in their description of the universe. Instead, they succeed in showing that the fluctuations can be generated directly from the quantum gravitational phase itself, the release said.