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| | *What methods of measuring H_0 do not depend on the cosmic distance ladder? | | *What methods of measuring H_0 do not depend on the cosmic distance ladder? |
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| − | *Describe how the SZ effect allows one to measure distances.
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| − | **Follow-up: What if the cluster were REALLY close to us? Would this method work well? (Hint: What would the angular extent of the cluster be? How would that compare to a typical scale of the "background" that's used in the SZ effect).
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| − | *How does one use quasars to measure H_0? Walk through exactly what's done (i.e. what do I do with my telescope, what do I plot etc.)
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| | The following was asked by MT | | The following was asked by MT |
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| | *Draw a log-log diagram with X-axis to be scale factor of the universe and Y-axis to be the density. Plot the density evolution of the universe on the diagram. | | *Draw a log-log diagram with X-axis to be scale factor of the universe and Y-axis to be the density. Plot the density evolution of the universe on the diagram. |
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| − | *Write down the Friedmann equation (in terms of Omegas). (SR)
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| − | **Interpreting this as an energy equation, what terms correspond to total energy, potential energy, and kinetic energy?
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| − | **How does the potential energy vary with the scale factor (draw a plot)?
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| − | **Calculate the scale factor at the maximum potential energy.
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| − | **Show where we are today on the plot.
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| − | *What does the l=1 multipole of the CMB power spectrum correspond to? (SH)
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| − | **What is the speed of the Earth around the sun? The Sun around the Galactic center? The Local Group with respect to the CMB?
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| − | *What sets the scale of the 1st Acoustic Peak in the CMB power spectrum? What's the sound speed in the photon baryon fluid? Derive the sound speed. Why is $P=1/3\rho$ for photons? Where does the 1/3 come from? (MT)
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| − | *WMAP often quotes an "optical depth to reionization." What is meant by this? Calculate this optical depth in terms of an integral over redshift. (MT)
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| − | *What is the difference between the density perturbations at matter-radiation equality and those at recombination? (MT)
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| − | *Given an equation of state parameter w, how does the density depend on scale factor?
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| − | **For what values of the equation of state parameter w will a substance cause the universe to accelerate? What is w for the cosmological constant? (MT)
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| − | *Explain how you can get matter-radiation equality?
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| − | **What time and z is this? (SR)
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| − | *Derive when the universe starts to accelerate. What is this value? (MT)
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| − | *What determines if the universe expands forever or collapses?
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| − | **What happens if Lambda is negative?
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| − | * What are three ways to get Omega baryons?
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| − | * When is/isn't surface brightness conserved?
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| − | [[Astrophysics]]
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