Choose the correct statements from the following list. (Give ALL correct answers, i.e., B, AC, BCD...) A) The inflationary model of the universe solves both the flatness and the horizon problems. B) The critical density is the density needed to cause the Big Bang. C) The horizon problem in cosmology is that regions of the universe that should not have ever had thermal contact with one another have the same temperature. D) A major difference between dark matter and dark energy is that one causes the univserse's expansion to slow down, the other to make it expand faster. E) Observations show us that the geometry of our universe must be very close to flat. F) Assuming no dark energy, if the matter density of the universe is less than critical, the universe is closed. G) Assuming no dark energy, if the matter density of the universe is greater than critical, the universe is will expand forever.

Choose the correct statements from the following list. (Give ALL correct answers, i.e., B, AC, BCD...) A) The inflationary model of the universe solves both the flatness and the horizon problems. B) The critical density is the density needed to cause the Big Bang. C) The horizon problem in cosmology is that regions of the universe that should not have ever had thermal contact with one another have the same temperature. D) A major difference between dark matter and dark energy is that one causes the univserse's expansion to slow down, the other to make it expand faster. E) Observations show us that the geometry of our universe must be very close to flat. F) Assuming no dark energy, if the matter density of the universe is less than critical, the universe is closed. G) Assuming no dark energy, if the matter density of the universe is greater than critical, the universe is will expand forever.