How can inflation explain the universe's large-scale uniformity?

Inflation explains the large-scale uniformity of the universe by addressing the "light-horizon" problem, which notes that distant regions of the sky appear to have the same temperature despite being too far apart to have exchanged information since the beginning of the universe.12

Before the period of rapid inflation, the matter and radiation that now constitute the entire observable universe were in close proximity and thermal contact, allowing them to reach a uniform temperature and acquire identical thermodynamic characteristics.12

During the inflationary era, a massive repulsive force caused the universe to expand exponentially, pushing these previously connected regions far beyond each other's individual event horizons. As the universe later resumed normal expansion, these distinct portions reappeared on our horizon. Because they were in thermal equilibrium before being separated, they maintain the same temperature, which is observed today as the high degree of isotropy in the cosmic microwave background.12