# Physicists Probe Into The Predictive Power Of Quantum Theory

Question asked by smriti in #Coffee Room on Jul 23, 2012

smriti · Jul 23, 2012

Rank C3 - EXPERT

A team of physicists led by Terence E. Stuart, from the University of Calgary in Alberta, Canada; ETH Zurich in Switzerland; and the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, Canada have published a paper investigating the predictive power of a quantum theory in a recent issue of <em>Physical Review Letters</em>. Years of experimental research and work along with the recent research work done by the physicists has led them to believe that that quantum theory, even with its shortcomings, is the optimal way of predicting outcomes.

It is known that certain outcomes of Quantum theory are only "random" in nature. In this scenario, the concept of hidden variable would allow 100% accuracy in prediction but physicist John Bell had already ruled out the existence of any hidden variable that would provide complete ascertainment. Though he didn't refute the existence of any alternative probabilistic theory that could have better outcomes or controvert any scope of improvement in quantum theory. Tony Legett model, which debuted in 2003, used a hidden spin vector which could increase the predictive probability of quantum theory by 0.25, from 0.5 to 0.75 but was declared a misfit for quantum theory.

In this paper published by the physicists, they have reasoned that there exists no alternate theory that could increase the predictive probability of quantum theory by more than 0.165. This means that any future theory which produces an advance in probability by more than 0.165 would be invalid either by Leggett’s model or by de Broglie-Bohm theory. For further reference, the published paper can be referred here.

Source: PhysOrg Image Credit: physicsforums Posted in: #Coffee Room

It is known that certain outcomes of Quantum theory are only "random" in nature. In this scenario, the concept of hidden variable would allow 100% accuracy in prediction but physicist John Bell had already ruled out the existence of any hidden variable that would provide complete ascertainment. Though he didn't refute the existence of any alternative probabilistic theory that could have better outcomes or controvert any scope of improvement in quantum theory. Tony Legett model, which debuted in 2003, used a hidden spin vector which could increase the predictive probability of quantum theory by 0.25, from 0.5 to 0.75 but was declared a misfit for quantum theory.

In this paper published by the physicists, they have reasoned that there exists no alternate theory that could increase the predictive probability of quantum theory by more than 0.165. This means that any future theory which produces an advance in probability by more than 0.165 would be invalid either by Leggett’s model or by de Broglie-Bohm theory. For further reference, the published paper can be referred here.

Source: PhysOrg Image Credit: physicsforums Posted in: #Coffee Room