Inflation 

byRobert Nemiroff

Michigan Technological University

Physics X: About This Course

• Officially "Extraordinary Concepts in Physics"• Being taught for credit at Michigan Tech

o Light on math, heavy on concepts o Anyone anywhere is welcome

• No textbook requiredo Wikipedia, web links, and lectures onlyo Find all the lectures with Google at:

"Starship Asterisk" then "Physics X"  o http://bb.nightskylive.net/asterisk/viewforum.php?f=39

Problems with Original Big Bang

• Horizon problemo Why is the universe so uniform?o How does the left part of the universe know to have the

same temperature as the right part?

• Flatness problemo Why is the geometry of the universe so close to flat?

• Magnetic monopole problem

Forces in the Universe

• Gravity• Electromagnetism• Strong Nuclear Force• Weak Nuclear Force

• Electroweak force• Grand unified theories• Superstring theories

http://universe-review.ca/I02-01-unify.jpg

Inflation to the Rescue

• Universe suddenly begins to expand exponentially• Caused by phase transition as strong nuclear force

freezes out• A repulsive “cosmological constant” temporarily

dominates the energy density of the universe• As inflation ends, matter and radiation are again created

o Why inflation ends is related to the driving field, but is really unknown.

Timeline for the Early Universe

• t=10-43 sec, T=1033 Ko Planck scale: theory of everything

• t=10-37 sec, T=1029 Ko Grand unified theory phase transitiono Strong nuclear force freezes outo Inflation

• T=10-35 sec, T=1028 Ko Inflation endso Particles created

http://www.greenspirit.org.uk/resources/inflation.JPG

Inflating the UniverseCredit: WMAP Science Team, NASA APOD: 2006 March 23

A Force from Empty Space: The Casimir EffectCredit & Copyright: Umar Mohideen (U. California at Riverside)APOD: 2002 September 17