Zenith Grant Awardee
Gregor Weihs
University of Innsbruck
Co-Investigators
Caslav Brukner, University of Vienna
Project Title
Higher-order Interferences and Time in Alternatives to Quantum Theory
Project Summary
Quantum theory has been with us for about a century almost in its present form. While it provides us with excellent tools to calculate the inner workings of matter and the power to create technology that we would have termed science fiction only a few years ago there are still many things that we don't understand about it – why is quantum theory the way it is? Furthermore, quantum theory seems to resist our desire to unify it with a description of gravity – Could we modify quantum theory to make it compatible?
In our project, we will explore some alternatives to quantum theory and quantum theory with small modifications. Theoretical studies and quantum optical experiments will show us whether these alternatives and modifications could be consistent with what we find in nature. If so, our findings may point us in the right direction for a unified theory, or the understanding of the quantum classical boundary. If, instead, we find that these alternatives can be refuted, we will know that we have to focus our efforts elsewhere.
Technical Abstract
Quantum mechanics appears to be a rigid island in theory space that doesn't allow for small modifications without ruining the whole construct. And yet, it seems clear that without such modifications we won't see a quantum theory of gravitation. In this project, we will explore the sea around this island by investigating alternative probabilistic theories with modified probability rules and / or modified state representation using hypercomplex numbers.
In our theory work we will elucidate the properties of theories based on quaternion and other hypercomplex numbers and design interferometric tests of these theories vs. standard quantum mechanics. We will further examine the role of time in theories that could possess multiple timelike dimensions. Finally we will look into simulations of such higher-level theories using ordinary quantum mechanics to analyze computational complexity in the light of varying representations of information.
On the experimental side, we will use our expertise gained in triple slit experiments in order to improve the bound on deviations from Born's rule or the presence of multi-order interference. Theories based on hypercomplex numbers can be tested using similar experiments and we will implement these tests, once they have been sufficiently refined in the theory part.
QSpace Latest
PressRelease: Shining a light on the roots of plant “intelligence”
All living organisms emit a low level of light radiation, but the origin and function of these ‘biophotons’ are not yet fully understood. An international team of physicists, funded by the Foundational Questions Institute, FQxI, has proposed a new approach for investigating this phenomenon based on statistical analyses of this emission. Their aim is to test whether biophotons can play a role in the transport of information within and between living organisms, and whether monitoring biophotons could contribute to the development of medical techniques for the early diagnosis of various diseases. Their analyses of the measurements of the faint glow emitted by lentil seeds support models for the emergence of a kind of plant ‘intelligence,’ in which the biophotonic emission carries information and may thus be used by plants as a means to communicate. The team reported this and reviewed the history of biophotons in an article in the journal Applied Sciences in June 2024.