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Clocks in the Universe are tricky things. Usually, in calculations of the birth of the world, a special scalar field plays the role of a clock — something like an invisible fluid filling all of space. It ticks, and physicists watch how the world changes relative to that ticking. But these clocks are man-made, introduced for convenience.

The authors of the new work took a different path. They based their approach on unimodular loop quantum cosmology — a framework where spacetime curvature itself sets the rhythm. Here, time is not tied to any particular substance but emerges from geometry. It's as if the course of events were determined not by the hands on a dial, but by the very movement of the mechanism. This step makes the theory cleaner: no need to invent a special clock field; the fabric of the cosmos suffices.

The researchers derived simplified equations for the early Universe and found solutions for several cases. For example, for a constant field energy, like a flat landscape, they obtained exact formulas. For more realistic scenarios, such as a quadratic potential and Starobinsky inflation, they had to resort to numerical calculations. In all variants, the Universe undergoes a 'bounce': contraction gives way to expansion without a singularity — a point of infinite density.

The main takeaway is that this approach is not only more elegant but also leaves potential traces in the observable sky. If quantum gravitational effects indeed influenced the early Universe, their imprints may survive in the large-scale structure of the cosmos. The geometry of time might not be just a mathematical trick, but a key to testing the theory.