They are basically just analogues of each other. The Schroedinger equation is based around a quantum version of classical Hamiltonian mechanics. By the same token, the path integral is built around a quantum version of Lagrangian mechanics. Another thing to consider is that the classical limit of the path integral is the traditional Lagrangian path. This can be found by taking Planck's constant, \hbar, to the limit of zero. Or, in another way of looking at it, the classical path is the stationary path of the path integral.
There are a lot of these little relationships that you can make between the two but most of these (like the classical limit) are obviously expected for the quantum path integral to make sense. And there is a bunch of formalism behind this. Can't recall a good reference that explains this though...
#3
sourena
13
0
Can the relationship between the quantum mechanical path integral and
classical mechanics be stated as this?
A path integral involves an exponential of the action S.
I am not sure if this belongs in the biology section, but it appears more of a quantum physics question.
Mike Wiest, Associate Professor of Neuroscience at Wellesley College in the US. In 2024 he published the results of an experiment on anaesthesia which purported to point to a role of quantum processes in consciousness; here is a popular exposition:
https://neurosciencenews.com/quantum-process-consciousness-27624/
As my expertise in neuroscience doesn't reach up to an ant's ear...
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles.
Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated...
Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/
by @RUTA
I am reading WHAT IS A QUANTUM FIELD THEORY?" A First Introduction for Mathematicians.
The author states (2.4 Finite versus Continuous Models) that the use of continuity causes the infinities in QFT:
'Mathematicians are trained to think of physical space as R3. But our continuous model of
physical space as R3 is of course an idealization, both at the scale of the very large and
at the scale of the very small. This idealization has proved to be very powerful, but in the
case of Quantum...