GRAVITY AS A SOURCE OF PHASE-TRANSITIONS

After going through several distinguished examples, we argue that grav ity is definitely a source of phase transitions of quite different nat ure: usual scalar effective potential ones, chiral symmetry transition s and even transitions involving the chromomagnetic vacuum. In such co ntext, we emphasize the fact that curvature-induced phase transitions of those kinds - where an interplay between general relativity and ele mentary particle physics occurs - can be used in the construction of n ew models of the inflationary universe.