Physicists search for new physics in primordial quantum fluctuations

Inflation, the brief period that occurred less than a second after the Big Bang, is nearly as difficult to fathom as the Big Bang itself. Physicists calculate that inflation lasted for just a tiny fraction of a second, yet during this time the Universe grew in size by a factor of 10⁷⁸. Also during this time, a very important thing occurred: fluctuations in the quantum vacuum appeared, which later resulted in the temperature fluctuations in the cosmic microwave background (CMB) that in turn produced large-scale structures such as galaxies. But in a new study, physicists now think that their understanding of the features of primordial quantum fluctuations – also called the inflationary power spectrum – may require a few small corrections due to currently unknown physics. These new corrections could allow scientists to search for experimental evidence to test a variety of quantum gravity theories, including string theory.