A Causal Framework for Non-Linear Quantum Mechanics

Understand

We add non-linear and state-dependent terms to quantum field theory.

• We show that the resulting low-energy theory, non-linear quantum mechanics, is causal, preserves probability and permits a consistent description of the process of measurement.
• We explore the consequences of such terms and show that non-linear quantum effects can be observed in macroscopic systems even in the presence of de-coherence.
• We find that current experimental bounds on these non-linearities are weak and propose several experimental methods to significantly probe these effects.