From "Computer-generated holography with ordinary display" (2024) https://opg.optica.org/viewmedia.cfm?r=1&rwjcode=ol&uri=ol-4... :

> The hologram cascade is synthesized by solving an inverse problem with respect to the propagation of incoherent light.

From "Learning quantum Hamiltonians at any temperature in polynomial time" (2024) https://arxiv.org/abs/2310.02243 .. https://news.ycombinator.com/item?id=40396171 :

>> The relaxation technique is well known in the field of approximation algorithms, but it had never been tried in quantum learning.

Relaxation (iterative method) https://en.wikipedia.org/wiki/Relaxation_(iterative_method)

Pertubation theory > History > Beginnings in the study of planetary motion ... QFT > History:
https://en.wikipedia.org/wiki/Perturbation_theory#Beginnings...

QFT > History: https://en.wikipedia.org/wiki/Quantum_field_theory#History :

> Quantum field theory emerged from the work of generations of theoretical physicists spanning much of the 20th century. Its development began in the 1920s with the description of interactions between light and electrons, culminating in the first quantum field theory—quantum electrodynamics. A major theoretical obstacle soon followed with the appearance and persistence of various infinities in perturbative calculations, a problem only resolved in the 1950s with the invention of the renormalization procedure. A second major barrier came with QFT's apparent inability to describe the weak and strong interactions, to the point where some theorists called for the abandonment of the field theoretic approach. The development of gauge theory and the completion of the Standard Model in the 1970s led to a renaissance of quantum field theory.

But the Standard Model Lagrangian doesn't describe n-body gravity, n-body quantum gravity, photons in Bose-Einstein Condensates; liquid light in superfluids and superconductors, black hole thermodynamics and external or internal topology, unreversibility or not, or even fluids with vortices or curl that certainly affect particles interacting in multiple fields.

TIL again about Relaxation theory for solving quantum Hamiltonians.

OTOH other things on this topic

- "Coherent interaction of a-few-electron quantum dot with a terahertz optical resonator" (2023) https://arxiv.org/abs/2204.10522 :

> By illuminating the system with THz radiation [a wave function (Hamiltonian) is coherently transmitted over a small chip-scale distance]

- "Room Temperature Optically Detected Magnetic Resonance of Single Spins in GaN" (2024) https://www.nature.com/articles/s41563-024-01803-5 ... "GAN semiconductor defects could boost quantum technology" https://news.ycombinator.com/item?id=39365467

- "Reversible non-volatile electronic switching in a near-room-temperature van der Waals ferromagnet" (2024) https://www.nature.com/articles/s41467-024-46862-z ... "Nonvolatile quantum memory: Discovery points path to flash-like qubit storage" (2024) https://news.ycombinator.com/item?id=39956368 :

>> "That's the key finding," she said of the material's switchable vacancy order. "The idea of using vacancy order to control topology is the important thing. That just hasn't really been explored. People have generally only been looking at materials from a fully stoichiometric perspective, meaning everything's occupied with a fixed set of symmetries that lead to one kind of electronic topology. Changes in vacancy order change the lattice symmetry. This work shows how that can change the electronic topology. And it seems likely that vacancy order could be used to induce topological changes in other materials as well."

- "Catalog of topological phonon materials" (2024) https://www.science.org/doi/10.1126/science.adf8458 ... "Topological Phonons Discovered and Catalogued in Crystal Lattices" (2024-05) https://news.ycombinator.com/item?id=40410475

- "Observation of current whirlpools in graphene at room temperature" (2024) https://www.science.org/doi/10.1126/science.adj2167 .. "Electron Vortices in Graphene Detected" https://news.ycombinator.com/item?id=40360691 :

> re: the fractional quantum hall effect, and decoherence: How are spin currents and vorticity in electron vortices related?