What property of evolution keeps total probability at 1?

• Linearity alone
• Unitarity
• Reversing time

For a time-independent Hamiltonian, what evolves the state?

• The exponential of minus i H t
• The Hamiltonian squared
• The inverse temperature

In the Heisenberg picture, operators carry the time dependence and states stay fixed.

Circle one:   True   False

You apply U of t to the starting state. What do you hold?

• The measurement record
• The state at time t
• The Hamiltonian eigenvalues

A superposition of two energy states evolves freely. What stays fixed?

• Each part phase
• The energy difference
• Each part probability

Both pictures predict one experiment. How do the predictions compare?

• Heisenberg predicts sharper values
• The moving-state picture predicts more
• They always agree

Your question concerns an observable at many times. Which picture shortens the work?

• Heisenberg, evolving the one operator
• Moving-state, re-evolving each state
• Neither, both need equal algebra

A student says rotating phases must shrink the probabilities. What is wrong?

• Phases rotate the state out of space
• Unitary rotation preserves every length
• Probabilities live outside the state