Description of Gluon Propagation in the Presence of an A^2 Condensate

There is a good deal of current interest in the condensate A^2 which has been seen to play an important role in calculations which make use of the operator product expansion. That development has led to the publication of a large number of papers which discuss how that condensate could play a role in a gauge-invariant formulation. In the present work we consider gluon propagation in the presence of such a condensate which we assume to be present in the vacuum. We show that the gluon propagator has no on-mass-shell pole and, therefore, a gluon cannot propagate over extended distances. That is, the gluon is a nonpropagating mode in the gluon condensate. In the present work we discuss the properties of both the Euclidean-space and Minkowski-space gluon propagator. In the case of the Euclidean-space propagator we can make contact with the results of QCD lattice calculations of the propagator in the Landau gauge. With an appropriate choice of normalization constants, we present a unified representation of the gluon propagator that describes both the Minkowski-space and Euclidean-space dynamics in which the A^2 condensate plays an important role.Comment: 28 pages, 11 figure

Search Query: Can America Accept a Right to Be Forgotten as a Publicity Right?

Search engines have profoundly changed the relationship between privacy and free speech by making personal information widely and cheaply available to a global audience. This has raised many concerns both over how online companies handle the information they collect and how regular citizens use online services to invade other people’s privacy. One way Europe has addressed this change is by providing European Union citizens with a right to petition search engines to deindex links from search results—a so-called “right to be forgotten.” If the information contained in a search result is “inadequate, irrelevant or no longer relevant,” the search engine now has an obligation to make the link unsearchable on their platform in the EU. In the United States, no such right to be forgotten exists. Many scholars have argued that such a right is irreconcilable with the First Amendment and American notions of free speech, noting that European law places a higher premium on privacy over free speech than the American constitution will allow for. Up until now, commentators have framed the right to be forgotten as a privacy right. This article posits that conceptualizing the right to be forgotten as a publicity right would make it more palatable to American lawmakers, largely due to the fact it reframes a highly theoretical moral right as a concrete economic guarantee against a search engine’s unfair use of a person’s image, name, or likeness for profit

The Nielsen Identities for the Two-Point Functions of QED and QCD

We consider the Nielsen identities for the two-point functions of full QCD and QED in the class of Lorentz gauges. For pedagogical reasons the identities are first derived in QED to demonstrate the gauge independence of the photon self-energy, and of the electron mass shell. In QCD we derive the general identity and hence the identities for the quark, gluon and ghost propagators. The explicit contributions to the gluon and ghost identities are calculated to one-loop order, and then we show that the quark identity requires that in on-shell schemes the quark mass renormalisation must be gauge independent. Furthermore, we obtain formal solutions for the gluon self-energy and ghost propagator in terms of the gauge dependence of other, independent Green functions.Comment: 25 pages, plain TeX, 4 figures available upon request, MZ-TH/94-0

Relativistically Covariant Symmetry in QED

We construct a relativistically covariant symmetry of QED. Previous local and nonlocal symmetries are special cases. This generalized symmetry need not be nilpotent, but nilpotency can be arranged with an auxiliary field and a certain condition. The Noether charge generating the symmetry transformation is obtained, and it imposes a constraint on the physical states.Comment: Latex file, 9 page