The Conditions in the Early Universe at the Time Matter

question 97

Multiple Choice

The conditions in the early universe at the time matter became decoupled from radiation were (in terms of age t and equivalent temperature T) :

• A) t = 2 × 10¹¹ years , T = 3 K
• B) t = 3 minutes, T = 10⁷ K
• C) t = 380,000 years, T = 3000 K
• D) The universe was never radiation-dominated since matter has always dominated by generating the gravitational field into which the universe has expanded.

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