When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Precision tests of QED - Wikipedia

    en.wikipedia.org/wiki/Precision_tests_of_QED

    Quantum electrodynamics (QED), a relativistic quantum field theory of electrodynamics, is among the most stringently tested theories in physics. The most precise and specific tests of QED consist of measurements of the electromagnetic fine-structure constant, α, in various physical systems. Checking the consistency of such measurements tests ...

  3. Gauge fixing - Wikipedia

    en.wikipedia.org/wiki/Gauge_fixing

    Forward and backward polarized radiation can be omitted in the asymptotic states of a quantum field theory (see Ward–Takahashi identity). For this reason, and because their appearance in spin sums can be seen as a mere mathematical device in QED (much like the electromagnetic four-potential in classical electrodynamics), they are often spoken ...

  4. Quantum field theory - Wikipedia

    en.wikipedia.org/wiki/Quantum_field_theory

    In theoretical physics, quantum field theory (QFT) is a theoretical framework that combines classical field theory, special relativity, and quantum mechanics. [1]: xi QFT is used in particle physics to construct physical models of subatomic particles and in condensed matter physics to construct models of quasiparticles.

  5. Aharonov–Bohm effect - Wikipedia

    en.wikipedia.org/wiki/Aharonov–Bohm_effect

    It is generally argued that the Aharonov–Bohm effect illustrates the physicality of electromagnetic potentials, Φ and A, in quantum mechanics.Classically it was possible to argue that only the electromagnetic fields are physical, while the electromagnetic potentials are purely mathematical constructs, that due to gauge freedom are not even unique for a given electromagnetic field.

  6. Quantum electrodynamics - Wikipedia

    en.wikipedia.org/wiki/Quantum_electrodynamics

    In particle physics, quantum electrodynamics (QED) is the relativistic quantum field theory of electrodynamics. [ 1 ] [ 2 ] [ 3 ] In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved. [ 2 ]

  7. Electromagnetic field - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_field

    An electromagnetic field (also EM field) is a physical field, mathematical functions of position and time, representing the influences on and due to electric charges. [1] The field at any point in space and time can be regarded as a combination of an electric field and a magnetic field .

  8. Classical electromagnetism - Wikipedia

    en.wikipedia.org/wiki/Classical_electromagnetism

    The theory provides a description of electromagnetic phenomena whenever the relevant length scales and field strengths are large enough that quantum mechanical effects are negligible. For small distances and low field strengths, such interactions are better described by quantum electrodynamics which is a quantum field theory .

  9. Quantization of the electromagnetic field - Wikipedia

    en.wikipedia.org/wiki/Quantization_of_the...

    The quantization of the electromagnetic field is a procedure in physics turning Maxwell's classical electromagnetic waves into particles called photons. Photons are massless particles of definite energy , definite momentum , and definite spin .