M. G. Ganiou

Tuning a radio is a delicate business: one knob turns easily, another resists. In the physics of the early Universe, there are also 'knobs'—parameters that determine what we see today. One of them is the strength of the coupling between a special field (the one that drove the rapid expansion of the Universe) and the geometry of space.

In the first second after the Big Bang, the universe was a boiling cauldron of energy. Particle-antiparticle pairs were born and instantly annihilated each other. But for every billion such pairs, one particle of matter survived, and that leftover became stars, planets, and people. New research blames modified gravity for this.