Wavefunction collapse in modified Quantum Theory, Role of gravity and Possibility of Experimental Verification

It has been suggested that the collapse of the wave function during a quantum

measurement is possibly dynamical and can be explained by slightly modifying the 

Schroedinger equation. Such modifications were made by Ghirardi, Rimini and Pearle in 

their GRW and CSL models by putting non-linear and stochastic terms in the Schroedinger 

equation. Stochasticity is necessary for a random collapse of the wavefunction. Another 

approach to introduce  stochasticity is to say that it is a consequence of intrinsic fluctuations 

in the geometry of spacetime itself. Two different models have been proposed along this 

line by Karolyhazy and Diosi. In this talk I will discuss how fluctuating gravity can play a role 

in the wavefunction collapse mechanism where I will compare these two well-known 

models. I will also analyse whether such models are complete in understanding or lack some 

deeper physics.

Gravity induced collapse and other modified quantum theories such as CSL result in a tiny 

non-conservation of energy and momentum. This introduces a random motion similar to the 

Brownian motion which can, in principle, be tested in laboratory under low temperature 

and pressure. Following a previous work by Collett and Pearle, I will describe how these 

random motions generated by CSL as well as gravity models give rise to detectable 

translational / rotational motion.