Pop the popcorn

1 · Look at the newborn bubble

Beginner

What do the authors show about the bubble of true vacuum at the moment it is born?

It is a perfect sphere, as in the standard calculation It is flat, like a disc It is never exactly round

For a thin wall, the relative deformation per mode is δR/R ≈ 1.2 × (ℏ/S_b)^½, with S_b the bounce action.

Intermediate

For S_b/ℏ = 144, how far out of round is the wall, relative to the radius?

About 0.8% About 8% About 10%

The tunnelling rate falls as e^(−S_b/ℏ): a larger bounce action means a rarer bubble.

Expert

If the bounce action were 4 times larger, how would the relative deformation δR/R change?

Divided by 4 Divided by 2 Unchanged

Now the false vacuum is very light: its particles are so light that their natural range is much larger than the bubble (mR ≪ 1).

Expert

What then dominates the bubble's quadrupole?

Fluctuations along the bubble's long tail Internal vibrations of a thin wall The rigid displacement of the wall alone

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