What is quantum field theory? - New Scientist
Quantum field theory marries the ideas of other quantum theories to depict all particles as “excitations” that arise in underlying fields. The British physicist Paul Dirac started the ball ...
What is the difference between Quantum Physics, Quantum …
Quantum field theory (QFT) is a theoretical framework for constructing quantum mechanical models of subatomic particles in particle physics and quasiparticles in condensed matter physics, by treating a particle as an excited state of an underlying physical field.
What are Quantum Field Theories? - Physics Stack Exchange
Aug 17, 2023 · A field theory is a mathematical model where the "basic ingredients" are fields. Maxwell's theory of electromagnetic fields and continuum mechanics are prominent examples of classical field theories. A quantum field theory is a quantum theory, where you promote fields to operators, roughly speaking.
The vacuum in quantum field theories: what is it?
Definition 1: A quantum state is said to be a vacuum state iff the expectation value of the Hamiltonian in this theory is a local minimum (the Hamiltonian of course being part of the data that defines the theory). Is this the correct notion of what it means to be the "physical vacuum" in a given theory? If so, two questions immediately come to ...
quantum field theory - Self Teaching QFT - Physics Stack Exchange
Dec 29, 2015 · "Quantum field theory for the gifted amateur" by Lancaster and Blundell is good. It would be good for you to know some basic calculus: integration, differentiation, Fourier transforms. It would also be useful to know some special relativity and quantum mechanics at the undergraduate level.
What is the fundamental probabilistic interpretation of Quantum …
In quantum field theory, the most natural basis (or the most widely used one) is the basis analogous to the harmonic oscillator energy eigenstate example. For each type of a quantum field, each polarization, and each $\vec k$ (the wavenumber, i.e. the frequency and the direction of motion), we define the contribution of this mode of the quantum ...
What is a complete book for introductory quantum field theory?
Peskin and Schroeder's An Introduction To Quantum Field Theory ; There is a list by Luboš Motl here; Mark Srendnick's Quantum Field Theory; Folland's Quantum field theory; These are recommendations from the older answers that did not follow the book policy. Plain recommendations are inappropriate now, try to explain what the book covers, its ...
quantum field theory - Online QFT video lectures - Physics Stack …
Abstract: The lectures are intended to provide an introduction to Quantum Field Theory at an elementary level. In particular, the following topics will be treated: 1, Basic principle of QFT; 2, Representation theory of the Poincaré group; 3, The free scalar field; 4, The free Dirac field 5, Interacting field theories; 6, Supersymmetry; 7, S ...
Ether vs. Quantum Field Theory - Physics Stack Exchange
Jan 30, 2017 · In quantum field theory an electron traversing space time is described by a quantum mechanical wave packet (which means that what "waves" is the probability of existing at (x, y, z, t)), manifested by creation and annihilation operators acting on the electron field, and the expectation value defines the location of the electron as a function of ...
quantum field theory - Are standard QFT and general relativity ...
Apr 14, 2020 · So, the usual textbook formulation even of quantum field theory is as a mechanics that just happens to have an infinite number of variables: the value of the fields at each position on any of the three-dimensional slices is counted as a separate variable, for the purposes of treating the system like a glorified form of mechanics. You can set it ...