# Index [[Antiparticles]] [Charge operator](Charge%20operator.md) [Normal ordering](Normal%20ordering.md) [[Path ordering]] [Quantum mechanical particles](Quantum%20mechanical%20particles.md) [[Time ordering]] [[The vacuum state]] ## Sub-Indices [[Relativistic Quantum Mechanics (index)]] --- # Basic concepts ## Motivation Quantum Field Theory is the version of quantum mechanics that allows us to understand interactions between particles at the _fundamental level_. Without quantum field theory one at most considers [ensembles](Ensembles%20of%20quantum%20systems.md) of countably many particles that may interact, however, we only model how those interactions affect individual particles as they encounter energy potentials that are invoked to model these interactions. Thus, quantum mechanics which ignores fields also doesn't account for the back-reaction on a measurement device. %%This isn't from any particular book, but it's an explanation from Hoffmann's lecture on quantum mechanics.%% --- # Bibliography Hoffmann S., _Exercises on Quantum Mechanics, Problem sheet 8_, Quantum Mechanics II (TM1/TV), 2020/2021  [Woit, Peter. _Quantum Theory, Groups and Representations: An Introduction_. Springer. 2017.](Woit,%20Peter.%20Quantum%20Theory,%20Groups%20and%20Representations%20An%20Introduction,%20Springer,%202017.md) Zee A. _Quantum Field Theory in a Nutshell_ %20-%20libgen.lc.pdf) #QuantumMechanics/RelativisticQuantumMechanics #QuantumMechanics/QuantumFieldTheory #QuantumMechanics/QuantumDynamics/PathIntegrals #QuantumMechanics/MultiParticleQuantumSystems #index #Bibliography