Quantum field theory

In quantum mechanics and quantum field theory, the propagator is a function that specifies the probability amplitude for a particle to travel from one place to another in a given time, or to travel with a certain energy and momentum.

In quantum mechanics, a parity transformation (also called parity inversion) is the flip in the sign of one spatial coordinate.

The path integral formulation of quantum mechanics is a description of quantum theory which generalizes the action principle of classical mechanics.

Functional integration is a collection of results in mathematics and physics where the domain of an integral is no longer a region of space, but a space of functions.

In particle physics, helicity is the projection of the angular momentum onto the direction of momentum.

In quantum mechanics, a boson (/ˈboʊsɒn/, /ˈboʊzɒn/) is a particle that follows Bose–Einstein statistics.

In particle physics, the Dirac equation is a relativistic wave equation derived by British physicist Paul Dirac in 1928.

In particle physics, a fermion (a name coined by Paul Dirac from the surname of Enrico Fermi) is any particle characterized by Fermi–Dirac statistics.

("God Particle" redirects here. For the upcoming sci-fi film, see God Particle (film).) The Higgs boson is an elementary particle in the Standard Model of particle physics.

In the Standard Model of particle physics, the Higgs mechanism is essential to explain the generation mechanism of the property "mass" for gauge bosons.

In quantum mechanics and particle physics, spin is an intrinsic form of angular momentum carried by elementary particles, composite particles (hadrons), and atomic nuclei.

In physics, an anyon is a type of quasiparticle that occurs only in two-dimensional systems, with properties much less restricted than fermions and bosons; the operation of exchanging two identical particles may cause a global phase shift but cannot affect observables.

A chiral phenomenon is one that is not identical to its mirror image (see the article on mathematical chirality).

In physics, quantization is the process of transition from a classical understanding of physical phenomena to a newer understanding known as quantum mechanics.

In particle physics, Fermi's interaction (also the Fermi theory of beta decay) is an explanation of the beta decay, proposed by Enrico Fermi in 1933.

In theoretical physics, the renormalization group (RG) refers to a mathematical apparatus that allows systematic investigation of the changes of a physical system as viewed at different distance scales.

Noether's (first) theorem states that every differentiable symmetry of the action of a physical system has a corresponding conservation law.

In physics, the S-matrix or scattering matrix relates the initial state and the final state of a physical system undergoing a scattering process.

In particle physics, the electroweak interaction is the unified description of two of the four known fundamental interactions of nature: electromagnetism and the weak interaction.

In the physics of gauge theories, gauge fixing (also called choosing a gauge) denotes a mathematical procedure for coping with redundant degrees of freedom in field variables.

A Majorana fermion (/maɪəˈrɒnə ˈfɛərmiːɒn/), also referred to as a Majorana particle, is a fermion that is its own antiparticle.

Although the Higgs boson, as included in the Standard Model, is arguably the simplest method of achieving the Higgs mechanism, it is not without problems.

In theoretical physics, a no-go theorem is a theorem that states that a particular situation is not physically possible.

In theoretical physics, quantum nonlocality is the phenomenon by which measurements made at a microscopic level contradict a collection of notions known as local realism that are regarded as intuitively true in classical mechanics.

Symmetries in quantum mechanics describe features of spacetime and particles which are unchanged under some transformation, in the context of quantum mechanics, relativistic quantum mechanics and quantum field theory, and with applications in the mathematical formulation of the standard model and condensed matter physics.

Axiomatic quantum field theory is a mathematical discipline which aims to describe quantum field theory in terms of rigorous axioms.

The quantum electrodynamic vacuum or QED vacuum is the field-theoretic vacuum of quantum electrodynamics.

In theoretical physics and mathematics, the Wess–Zumino–Witten (WZW) model, also called the Wess–Zumino–Novikov–Witten model, is a simple model of conformal field theory whose solutions are realized by affine Kac–Moody algebras.

In relativistic quantum mechanics and quantum field theory, the Bargmann–Wigner equations (or BW equations or BWE) are relativistic wave equations which describe free particles of arbitrary spin j, an integer for bosons (j = 1, 2, 3 ...) or half-integer for fermions (j =  1⁄2,  3⁄2,  5⁄2 ...).

In theoretical particle physics, the gluon field strength tensor is a second order tensor field characterizing the gluon interaction between quarks.

In quantum field theory, the vacuum state may be degenerate.

In quantum field theory, a Ward–Takahashi identity is an identity between correlation functions that follows from the global or gauge symmetries of the theory, and which remains valid after renormalization.

Schwinger's quantum action principle is a variational approach to quantum field theory introduced by Julian Schwinger.

The Thirring model is an exactly solvable quantum field theory which describes the self-interactions of a Dirac field in (1+1) dimensions.

The Thirring–Wess model or Vector Meson model is an exactly solvablequantum field theory describing the interaction of a Dirac field with a vector field in dimension two.

In quantum field theory, a composite field is a field defined in terms of other more "elementary" fields.

Quantum hadrodynamics is an effective field theory pertaining to interactions between hadrons, that is, hadron-hadron interactions or the inter-hadron force.

In particle physics, the history of quantum field theory starts with its creation by Paul Dirac, when he attempted to quantize the electromagnetic field in the late 1920s.

In theoretical physics, scalar field theory can refer to a classical or quantum theory of scalar fields.

In physics a free field is a field without interactions, which is described by the terms of motion and mass.