RUSSIA’S RELATIVISTIC ROAD TO INFLATION

Hints of gravitational waves, widely hailed as validation for inflation, could net someone a Nobel prize if they can be confirmed. But who came up with inflation in the first place? In 1980 Alan Guth, now at the Massachusetts Institute of Technology, gave his first public lecture on inflation, and he is often cited as a founder. But Guth wasn’t the only one pondering the theme. Aleksei Starobinksy of the Landau Institute for Theoretical Physics in Moscow, Russia, had published his own theory of inflation in December 1979. The paper appeared in a prominent Russian journal, and was later translated into English. Still,  it was largely overlooked. Viatcheslav Mukhanov of the Arnold Sommerfeld Center for Theoretical Physics in Munich, Germany, thinks this is because Starobinsky based his work on Einstein’s general theory of relativity. People in the field wanted testable predictions, and at the time any experiment to detect inflation seemed almost impossible to carry out, Mukhanov says. In contrast, he says, Guth’s ideas drew on particle physics – a playground for theorists – and so sparked widespread interest as a mathematical exercise. Starobinsky’s model was a better fit for our observations of the early universe until last week’s sighting of gravitational waves. Now it is unclear which of the competing theories of inflation will reign (see main story). “If the BICEP2 data are confirmed, apostles of inflation may celebrate the dramatic confirmation of the general idea of inflation, but not of any concrete simple model of it,”  says Starobinsky.  Stuart Clark