Model Universes ASTR/PHYS 4080: Intro to Cosmology Week 4 From - - PowerPoint PPT Presentation

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Model Universes ASTR/PHYS 4080: Intro to Cosmology Week 4 From - - PowerPoint PPT Presentation

Dec 02, 2023 365 likes •523 views

Model Universes ASTR/PHYS 4080: Intro to Cosmology Week 4 From https://commonphysics.wordpress.com/tag/physics/, where the tag line is In science there is only physics, all the rest is stamp collecting. Such hubris is why were still

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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

Model Universes

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ASTR/PHYS 4080: Intro to Cosmology Week 4

From https://commonphysics.wordpress.com/tag/physics/, where the tag line is “In science there is

  • nly physics, all the rest is stamp collecting.” Such hubris is why we’re still stuck with string theory.
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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

Evolution of Components

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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

CMB dominates energy density of photons in universe today Don’t know the mass of neutrinos, but energy density dominated by momentum and decoupling in early universe. Calculated to be: True for each neutrino flavor, so total is 3x above.

Relativistic Component: “Radiation” = Photons + Neutrinos

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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

Relativistic, Non-rel., & Components

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Radiation Matter: Dark Energy: Using evolution of each component with a, can compute when matter- dark energy and matter-radiation components were comparable

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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

Model Universes

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Can now solve for a(t) generically, if not necessarily analytically:

  • Empty
  • Matter only
  • classic case: open, closed, flat
  • Radiation only (+curvature)
  • Lambda only (+curvature)
  • Various Combinations!
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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

Empty

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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

Only 1 Constituent in a Flat Spacetime

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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

Only 1 Constituent in a Flat Spacetime

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m empty r m empty r

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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

Classical Cosmology: Matter + Curvature

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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

Classical Cosmology: Matter + Curvature

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Density —> Destiny

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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

Flat: Matter + Cosmological Constant

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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

Matter + Lambda + Curvature

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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

Benchmark Model

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−10 −8 −6 −4 −2 −6 −4 −2 2 log(H0t) log(a)

trm tmΛ t0 a∝t

1/2

a∝t

2/3

a∝e

Kt

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Spring 2018: Week 04 ASTR/PHYS 4080: Introduction to Cosmology

Benchmark Model

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