A Gravity Theory That Could Rewrite the Universe’s First Moments The first fraction of a second after the Big Bang has always posed a problem. Physics can describe a great deal about the universe once it cooled and expanded, but the very beginning, when temperatures and energies were extreme, has remained harder to pin down. A new study from researchers at the University of Waterloo and the Perimeter Institute argues that the universe’s earliest growth spurt may not need the extra theoretical add-ons that many cosmologists have relied on for decades. Instead, the team says that rapid early expansion, known as inflation, could emerge from a more complete version of gravity itself. That matters because Einstein’s general relativity, despite its long record of success, is not enough on its own in such extreme conditions. It works well as an effective theory, but breaks down at very high energies and runs into problems such as singularities and mathematical inconsistencies. Ruolin Liu, a PhD student at Perimeter and Waterloo, and Dr. Jerome Quintin, a lecturer at l’École …