Study could lead to discovery of signs of the Big Bang – 06/29/2023 – Science

As well as the detection of background radiation in microwaves (a signal coming from all directions that represents a kind of echo of the Big Bang, the first moment since the emergence of the universe, 13.8 billion years ago, in which light traveled unimpeded through it), the gravitational wave background now detected by NanoGrav, as further explored, could reveal much about the past and present of the cosmos.

In a first moment, it may reveal more details about this particular population of objects, the binary supermassive black holes. If at first all that was detected was an indistinct background that possibly represents the action of all of them together, this refined information will already allow estimating the frequency and variety they occur throughout the universe.

Later on, it is expected that the refinement in the observations will allow the detection of specific signals coming from some of these objects, so that they can be studied not only through their gravitational waves, but also by the light radiation they emit.

Finally, it is expected that amidst the “symphony” of the background of gravitational waves, it will be possible to detect signals that are the result of the Big Bang itself, or of the inflationary process that must have occurred soon after it (in which the universe grew rapidly, expanding faster than light), giving clues to how, in detail, the birth of the cosmos would have been.

Invited to participate in the event, physicist Kip Thorne (winner of the 2017 Nobel Prize in Physics for his work with the pioneering detection of gravitational waves with Ligo) highlighted this possibility.

“For me, the Holy Grail of this field, in the long term, is to explore the birth of the universe and extract this information that is carried by gravitational waves”, he says. “The conventional wisdom of theoretical physics says that these gravitational waves would be too weak for the NanoGrav to see. But in my 60-year career as a physicist, I have seen the conventional wisdom fail spectacularly on several occasions. I remain hopeful that some of the waves gravitational forces that NanoGrav saw are primordial, or from the Big Bang.”