Editing Cosmic inflation (section)

===Slow-roll inflation===
The bubble collision problem was solved by [[Andrei Linde]]<ref name="linde">{{cite journal |last1=Linde |first1=Andrei |date=1982 |title=A new inflationary universe scenario: A possible solution of the horizon, flatness, homogeneity, isotropy and primordial monopole problems |journal=[[Physics Letters B]] |volume=108 |issue=6 |pages=389–393 |bibcode=1982PhLB..108..389L |doi=10.1016/0370-2693(82)91219-9}}</ref> and independently by [[Andreas Albrecht (cosmologist)|Andreas Albrecht]] and [[Paul Steinhardt]]<ref name="albrecht">{{cite journal |doi=10.1103/PhysRevLett.48.1220 |title=Cosmology for Grand Unified Theories with Radiatively Induced Symmetry Breaking |date=1982 |last1=Albrecht |first1=Andreas |last2=Steinhardt |first2=Paul |journal=[[Physical Review Letters]] |volume=48 |issue=17 |pages=1220–1223 |bibcode=1982PhRvL..48.1220A |url=http://astrophysics.fic.uni.lodz.pl/100yrs/pdf/07/060.pdf |archive-url=https://web.archive.org/web/20120130063002/http://astrophysics.fic.uni.lodz.pl/100yrs/pdf/07/060.pdf |archive-date=30 January 2012  }}</ref> in a model named ''new inflation'' or ''slow-roll inflation'' (Guth's model then became known as ''old inflation''). In this model, instead of tunneling out of a false vacuum state, inflation occurred by a [[scalar field]] rolling down a potential energy hill. When the field rolls very slowly compared to the expansion of the Universe, inflation occurs. However, when the hill becomes steeper, inflation ends and reheating can occur.