Editing Cosmic inflation (section)

===Hybrid inflation===
Another kind of inflation, called ''hybrid inflation'', is an extension of new inflation. It introduces additional scalar fields, so that while one of the scalar fields is responsible for normal slow roll inflation, another triggers the end of inflation: when inflation has continued for sufficiently long, it becomes favorable to the second field to decay into a much lower energy state.<ref>{{Cite conference|last1= Brandenberger|first1= Robert H.|title= A Status Review of Inflationary Cosmology|year= 2001|arxiv=hep-ph/0101119|bibcode=2001hep.ph....1119B}}</ref>

In hybrid inflation, one scalar field is responsible for most of the energy density (thus determining the rate of expansion), while another is responsible for the slow roll (thus determining the period of inflation and its termination). Thus fluctuations in the former inflaton would not affect inflation termination, while fluctuations in the latter would not affect the rate of expansion. Therefore, hybrid inflation is not eternal.<ref>{{Cite journal|last1=Linde|first1=Andrei|last2=Fischler|first2=W.|year=2005|title=Prospects of Inflation|journal=[[Physica Scripta]]|volume=117|issue=T117|pages=40–48|arxiv=hep-th/0402051|bibcode=2005PhST..116...56B|doi=10.1238/Physica.Topical.117a00056|s2cid=17779961}}</ref><ref>{{Cite journal|last1=Blanco-Pillado|first1=J. J.|last2=Burgess|first2=C. P.|last3=Cline|first3=J. M.|last4=Escoda|first4=C.|last5=Gomez-Reino|first5=M.|last6=Kallosh|first6=R.|last7=Linde|first7=A.|last8=Quevedo|first8=F.|year=2004|title=Racetrack Inflation|journal=[[Journal of High Energy Physics]]|volume=2004|issue=11|pages=063|arxiv=hep-th/0406230|bibcode=2004JHEP...11..063B|doi=10.1088/1126-6708/2004/11/063|s2cid=12461702}}</ref> When the second (slow-rolling) inflaton reaches the bottom of its potential, it changes the location of the minimum of the first inflaton's potential, which leads to a fast roll of the inflaton down its potential, leading to termination of inflation.