There has been a development regarding the usage of Steepest Entropy Ascent formalism which modifies QM by incorporating the second law of thermodynamics in the formalism itself. The research shows that this is quite a consistent modification, including preclusion of signaling and other things. However, this approach is motivated by the requirements of consistency with thermodynamics, and not from the information theoretical approach.

You may check the following works, they might be of interest.

https://dx.doi.org/10.1098/rsta.2019.0168,

https://dx.doi.org/10.1103/PhysRevA.91.013848,

https://dx.doi.org/10.1103/PhysRevE.90.042113,

And some recent work shedding light on this

https://arxiv.org/search/quant-ph?searchtype=author&query=Ray%2C+R+K

Quantum information theory is, simply, an application of quantum mechanics, nothing more or less.

The only topic, where a modification of quantum mechanics itself might be relevant, is quantum gravity. Gerard ’t Hooft has been working on this for some time. Cf. https://arxiv.org/abs/1902.10469, for instance.

Philippos Afxentiou The struggle to make sense of quantum theory is focussed on the physical description associated with the mathematical models. I don’t think that adjusting the mathematical models with consistent modifications will help with this.

The attempts to resolve the conflict between quantum theory and general relativity have been aimed at extending quantum theory models.

What I think we are looking for is a new description of the fundamental nature of matter which can then be modelled mathematically in a new way. Then the challenge will be to show that the results from the new model are the same as or equivalent to the experimental predictions of QM.

The starting point for this analysis is the recognition that the fundamental entity of the universe is the medium of space. Light is a wave in this medium and electrons protons and neutrons are looped waves in this medium .

Data Prerecording of Conference Presentation on the Unification of Physics

Richard

Many flaws in quantum physics, like superposition, entanglement, complementarity, follow from inadequate mathematical structure. An old Einstein’s suggestion was that quantum mechanics is not the root level of reality, but merely hazy glimpse of something even deeper. But another idea may be that quantum mechanics is not of something deeper but should be replaced by something conceptually different. Some physicists say that the current conventional formalism is a very shaky foundation. Many details about alternative mathematical structure can be found in "The Geometric Algebra Lift of Qubits and Beyond."

I proposed a very simple interpretation of the principles of superposition and reduction of the wave function. Please see my little paper

Subquantum leapfrog Preprint Subquantum leapfrog

Quantum, strings are chord phenomena that cannot be understood outside of chords.

Preprint Chord Language

Preprint Chord Spacetime

Dear Philippos Afxentiou

A classical approach to quantum mechanics has been developed in the purview of stochastic electrodynamics a well known subject. In which the vacuum is filled with zero-point fields and the particles are normally treated as oscillators.

I am recently working on foundations of quantum mechanics in the purview of complex vector algebra. My recent works include

1. Common physical theory for quantum/classical particles in complex vector space. Quantum Stud.: Math. Found. 8, 249–259(2021). https://doi.org/10.1007/s40509-021-00243-z Read online at this link: https://rdcu.be/chh1i

2. Classical approach to the quantum condition and biaxial spin connection to Schrödinger equation. Quantum Stud.: Math. Found. 3, 31-39 (2016) https://doi.org/10.1007/s40509-015-0058-2

3. Theory of stochastic Schrodinger equation in complex vector space. Found. Phys. 47, 532-557 (2017) https://doi.org/10.1007/s10701-017-0076-5

4. Algebra of Complex vectors and Applications in Electromagnetic Theory and Quantum mechanics. K. Muralidhar, Mathmatics 3, 781-842 (2015) ; https://doi.org/10.3390/math3030781

5. Complex Vector Formalism of Harmonic Oscillator in Geometric Algebra: Mass, Spin and Dynamics in Complex Vector space. K Muralidhar, Found. Phys. 44, 266-295 (2014) ; https://doi.org/10.1007/s10701-014-9784-2

For about 3 decades there is research to implement gravity into QFT. But because QFT is some kind of a merge of older (quantum) theories some researchers in the field of quantum gravity wanted to make a fresh start. The research can be described as “Building spacetime from scratch” (for example: https://arxiv.org/abs/hep-th/0604212v1).

Unfortunately in practise these attempts to build a mathematical model of discrete (quantized) spacetime are limited to implementing known theories in the model. So it is not difficult to imagine that they will be confronted with the same type of difficulties as the more “traditional” approaches.

Anyway, the research is really promising because there is no reason why it couldn’t be successful if the focus is on the foundations of physics.

With kind regards, Sydney