Exam 19: Cosmology

In a primordial, pregalactic gas cloud, what is believed to have been the MOST important condition that caused the cloud to become an elliptical galaxy (as opposed to some other type of galaxy)?

What significant event occurred about 400,000 years after the start of the Big Bang?

What do cosmologists study?

How does the cosmological constant differ from quintessence?

Helium nuclei began permanent formation in the early universe when the temperature dropped to the point where the gamma radiation no longer had enough energy to break nuclei apart as soon as they formed. Did this helium production cease? If so, why?

What makes gravity the main force determining the large?-scale structure of the universe?

What kind of curvature (geometry of space) does the universe have if the universe is closed?

If the cosmic microwave background radiation is the radiation left over from the Big Bang, why is its temperature only 3 K?

Approximately when did the inflationary period begin?

What kind of curvature (geometry of space) does the universe have if the universe is just on the boundary between being open and being closed?

Why is flatness a problem in cosmology?

Suppose H₀ = 71 km/s/Mpc. What is H₀ in m/s/ly?

At what times during the Big Bang were all four fundamental forces unified?

What designation do astronomers give to the first stars?

The symmetry breaking that led to the existence of matter is MOST likely associated with which one of the fundamental forces?

What is the cosmic microwave background radiation?

What causes the cosmological redshift of photons that reach Earth from distant galaxies?