inflation why and how n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Inflation : why and how ? PowerPoint Presentation
Download Presentation
Inflation : why and how ?

Loading in 2 Seconds...

play fullscreen
1 / 20

Inflation : why and how ? - PowerPoint PPT Presentation


  • 120 Views
  • Uploaded on

Inflation : why and how ?. Gert Jan Hoeve, December 2012. Problems with the Hot Big Bang. Flatness | Ω -1|<10 16 at nucleosythesis Unwanted relics Horizon problem Homogeneity over parts of space that are presumably not causally correlated . Baryogenesis

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Inflation : why and how ?' - jeremy-castro


Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
inflation why and how

Inflation: whyandhow?

Gert Jan Hoeve, December 2012

problems with the hot big bang
Problemswith the Hot Big Bang
  • Flatness
        • |Ω-1|<1016 at nucleosythesis
  • Unwantedrelics
  • Horizon problem
    • Homogeneity over parts of spacethat are presumablynotcausallycorrelated.
  • Baryogenesis
    • Conventionaltheories of symmetrybreaking are insufficientfor the observedammount of baryons
the solution inflation
The solution: inflation

d2a/dt2 >> 0

or equivalently,

-(dH/dt)/H2 >> 1

Between Planck time (10-43) andGUT decoupling (10-35)

Alan Guth, 1981

Picture: Wikipedia

how does cosmic inflation solve the flatness problem
How does cosmicinflationsolve the flatnessproblem?
  • Ω is pushedtowards 1 duringinflation
  • ‘Stretching’
unwanted relics magnetic monopoles
Unwantedrelics: magneticmonopoles
  • Abundant at high temperature
  • Slow decay
why do we have a horizon problem
Why do we have a horizon problem?
  • Cosmic Microwave Background radiationoriginated 500,000 yearsafter the BB.
  • No causalcorrelationpossible
inflation solves the horizon problem
Inflationsolves the horizon problem:

Picture: one minute astronomer

how much inflation do we need
How muchinflation do we need?

Inflationends at t0 = 10-35 s, we are at t1 = 1017 s

In radiationdominateduniverse |Ω-1|proportional to time

|Ωnow-1| ≤ 10-2 |ΩGUT-1|≤ 10-54

Recall|Ω-1|=|k|/(Ha)2

Duringinflation H=constant, so|Ω-1|proportional to 1/a2

Total expansion > ~ 1027

baryogenesis
Baryogenesis
  • Three conditions (Sakharov’sconditions)
    • Baryon numberviolatinginteractions
      • obvious
    • C violationand CP violation
      • Becauseany B-violatinginteractionwouldbemirroredby a complementaryinteraction
    • Thermal non-equilibrium (or CPT violation)
      • Otherwise the backwardsreactionwouldbeequilly strong
b violating interactions
B-violatinginteractions
  • Standard model:

sphalerons

  • Differenceleptonnumber

andbaryonnumerconserved

  • Example:

(u+u+d)+(c+c+s)+(t+t+b)  e++μ++τ+

c and cp violation
C and CP violation
  • B-violatingprocess must outratesymmetricprocess
  • Both symmetries

must beviolated

thermal non equilibrium at baryogenesis
Thermal non-equilibrium at baryogenesis
  • Phasetransitionbubbles
  • Thermal energy gradient at bubbleedge
  • Local breakdown of time symmetry
how did inflation arise
How didinflationarise?

Scalar field V(φ) causesspontaneoussymmetrybreaking

First or second order phasetransition?

B. Clauwens , R. Jeanerot, D-term inflationafterspontaneoussymmetrybreaking

H. Bohringer

original model guth 1981
Original model (Guth, 1981)
  • False/real vacuum
  • First order phasetransition
  • Reheatingproblems
slow roll inflation linde 1982
Slow-rollinflation (Linde, 1982)
  • d2φ/dt2 + 3H dφ/dt = -dV(φ)/dφ
  • Friedman H2 = (1/2 dφ/dt+V(φ))/3 –k/a2
  • Inflationdecays as slopeincreases
  • H=(da/dt)/a
quintessential scalar field
Quintessentialscalar field
  • 5th fundamental force
  • Continueousdecayingscalar field
  • Couldexplaininflationanddark energy at the same time!
  • M. Trodden, Baryogenesisand the new cosmology, 2002
conclusion
Conclusion

Cosmologicalinflation is a viable hypothesis, but in desperate need of a more solid foundation (and experimental confirmation) from the realm of particle physics.