Quintessential inflation: A tale of emergent and broken symmetries

Understand

Quintessential inflation provides a unified description of inflation and dark energy in terms of a single scalar degree of freedom, the cosmon.

• We present here a comprehensive overview of this appealing paradigm, highlighting its key ingredients and keeping a reasonable and homogeneous level of details.
• After summarizing the cosmological evolution in a simple canonical case, we discuss how quintessential inflation can be embedded in a more general scalar-tensor formulation and its relation to variable gravity scenarios.
• Particular emphasis is placed on the role played by symmetries.