Inflation (2025)

This is a review article for The Review of Particle Physics 2026 (aka the Particle Data Book), appearing as Chapter 23. It forms a compact review of our understanding of cosmological inflation near the end of 2025. Topics included are Scalar Field Cosmology; Primordial Perturbations from Inflation; Models; Model Comparison; Constraints on Reheating; Beyond Single-Field Inflation; Initial-conditions and Fine-tuning; Future Probes of Inflation.