Ghirardi-Rimini-Weber theory

The Ghirardi-Rimini-Weber (GRW) theory is a proposed solution to the measurement problem in quantum mechanics. It suggests that while wave functions are complete representations of physical systems, they are not always governed by linear differential equations of motion. Instead, the GRW theory posits that a particle's wave function occasionally undergoes a random "jump," multiplying by a narrow bell-shaped curve. This process localizes the wave function, effectively causing a "collapse." For microscopic systems, these jumps are rare, but for macroscopic systems, they can dramatically convert superpositions of states into definite outcomes. This theory offers an alternative to other interpretations like the many-worlds interpretation.12