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T Theory / model P Prediction O Observation / discovery C Confirmation I Concept

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1980–1982 Model Cosmology

Cosmic inflation

Alan Guth · Alexei Starobinsky · Andrei Linde · Andreas Albrecht · Paul Steinhardt

When we knew

Timeline date1980–1982

Several researchers developed scenarios in which the very early Universe underwent a brief phase of extremely rapid expansion. The modern inflationary picture emerged through multiple models.

Why it mattered

Inflation offered explanations for the Universe's large-scale uniformity, near-flat geometry, and the origin of primordial fluctuations.

What came before

The hot Big Bang model succeeded but left puzzles about initial conditions and widely separated regions.

What came after

Predictions for primordial fluctuations were tested through increasingly precise observations of the cosmic microwave background.

Memory anchor

Inflation is an added early chapter, not another name for the Big Bang.