A Modification of Quantum Mechanics

<!--HTML--><p>We present a modification of quantum mechanics in which a specific class of state-dependent term is added to the Schroedinger Equation. &nbsp;We show that this term produces non-trivial effects which amount to the ‘wave function talking to itself’. &nbsp;We show that these effects are nevertheless causal (don’t violate relativity) while having profound experimental consequences. &nbsp;We also show that this modification has a simple embedding in local quantum field theory. &nbsp;While the physical effects are dramatic, they are also fickle, in that their strength depends on the cosmological history of the wave function of the universe. &nbsp;We will present proposals for laboratory (e.g., AMO), astrophysical, and cosmological tests that could be done to discover such an effect.</p>