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SUMMARY:Bilinear expansion of the photon quantum field and the emergence o
f classical mechanics from quantum field theory
DTSTART;VALUE=DATE-TIME:20110715T060000Z
DTEND;VALUE=DATE-TIME:20110715T063000Z
DTSTAMP;VALUE=DATE-TIME:20240617T224028Z
UID:indico-contribution-5084@events.saip.org.za
DESCRIPTION:Speakers: Jan Greben (CSIR)\nThe electro-magnetic field is exp
anded in a bilinear series consisting of products of quark creation and an
nihilation operators. This bilinear form is suggested by the equations of
motion for the electromagnetic field and provides a very powerful quantum
representation\, which is devoid of many of the technical problems associa
ted with standard quantization. In this approach the energy of the physica
l photon can be expressed as an expectation value of the energy-momentum t
ensor. The direct term already yields the correct result\, so one has to e
liminate the additional cross term to maintain this correct result. In ord
er to affect this elimination one needs to introduce a continuous set of
“hidden” quantum numbers\, which can be related to the classical posit
ional coordinate of the particle. These “big bang variables” are intro
duced as state labels\, just like the momentum variable. The quantum ampli
tudes are insensitive to the choice of these coordinates\, so that the int
roduction of classical coordinates does not conflict with standard quantum
field theory calculations or with the Heisenberg uncertainty principle. H
owever\, in a many-body system coherence make these coordinates emerge as
the relative classical coordinates. Hence\, classical mechanics emerges na
turally from many-body quantum field theory. Without violating quantum mec
hanics\, particles can thus be specified in terms of momentum and position
\, in clear analogy to classical physics and statistical mechanics. Compos
ite particle systems are then identified by having identical classical coo
rdinate labels\, while independent particles have distinct labels and are
not subject to the Pauli principle in the remaining variables.\n\nhttps://
events.saip.org.za/event/7/contributions/5084/
LOCATION: Acro5
URL:https://events.saip.org.za/event/7/contributions/5084/
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