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Name: Kevin
Status: other
Grade: 9-12
Country: USA
Date: Summer 2012

What is the difference between the concepts of inflation and expansion of the universe?

Inflation is a special type of expansion where the size of the universe grows exponentially with time,

size ~ exp ( t ).

A popular theory of cosmology suggests that the early universe underwent a very brief period of extremely rapid inflation. The rate of expansion then transitioned to a slower, power-law form,

size ~ t ^ #,

where the power, # is greater than zero, so the size continued to increase. Our universe is currently expanding in this power-law manner. However, many cosmologists believe that the universe is in the process of transitioning to a second period of exponential expansion (inflation), but with a much slower time scale.

Douglas Stanford

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