Question

How do you simulate a quantum gauge theory in a gauge with negative norms on a quantum computer?

Answer 1

There is a theorem that you can efficiently simulate any quantum system on a quantum computer (and it is known, and all but proven with Shor factoring, that you can't do this with a classical computer), but the computer is restricted to positive norm states (obviously), so the question is whether you can simulate the negative norm states, or whether you are restricted to simulating in physical gauges. It's a strange and potentially deep question

Answer 2

Quantum theory makes the issues of taking in the right equation variation.