相关论文: Vacuum Polarisation Tensors in Constant Electromag…
The string-inspired technique is used for a first calculation of the one-loop axialvector vacuum polarisation in a general constant electromagnetic field. A compact result is reached for the difference between this tensor and the…
In the second part of this series we apply the ``string-inspired'' technique to the calculation of one-loop amplitudes involving both vectors and axialvectors, as well as a general constant electromagnetic background field. The…
Motivated by several recent papers on string-inspired calculations in QED, we here present our own use of world-line techniques in order to calculate the vacuum polarization and effective action in scalar and spinor QED with external…
The one-loop vacuum polarization tensor is computed in QED with an external constant, homogeneous magnetic field at finite temperature. The Schwinger proper-time formalism is used and the computations are done in Euclidian space. The…
We develop worldline numerical methods, which combine string-inspired with Monte-Carlo techniques, for the computation of the vacuum polarization tensor in inhomogeneous background fields for scalar QED. The algorithm satisfies the Ward…
In this paper we study the polarization tensor of photons in a QED plasma in the presence of a magnetic field. We do it both at vanishing and at finite temperature. We use two different methods to compute the polarization tensor components…
The QED vacuum polarization in external monochromatic plane-wave electromagnetic fields is calculated with spatial and temporal variations of the external fields being taken into account. We develop a perturbation theory to calculate the…
The vacuum polarization tensor in strong external magnetic fields has been evaluated numerically for various strengths of magnetic fields and momenta of photons under the threshold of the $e^{\pm}$ pair creation. The fitting formula has…
We uncover a fundamental effect of the QED vacuum in an external electromagnetic (EM) field. We show that the quantized vacuum of electrons is spin polarized by the EM field and manifests as a vacuum spin current. An experiment is proposed…
It is explained how first-quantized worldline path integrals can be used as an efficient alternative to Feynman diagrams in the calculation of QED amplitudes and effective actions. The examples include the one-loop photon splitting…
In the framework of strong-field QED with $x$-steps, we study vacuum mean values of the current density and energy--momentum tensor of the quantized spinor field placed in the so-called $L$-constant electric background. The latter…
This is the second one of a series of four papers devoted to a first calculation of the scalar and spinor QED four-photon amplitudes completely off-shell. We use the worldline formalism which provides a gauge-invariant decomposition for…
We compute the photon polarization tensor at one-loop order in the presence of a constant and uniform electric field. Our calculation is carried out for arbitrary field strength using the Schwinger proper-time formalism, and we explicitly…
We study the main properties of the one-loop vacuum polarization function ($\Pi_{\alpha \beta}$) for spinor $QED$ in `$d + {1/2}$ dimensions', i.e., with fields defined on ${\mathcal M} \subset {\mathbb R}^{d+1}$ such that ${\mathcal M} =…
We study the main properties of the one-loop vacuum polarization function for massless spinor QED4 in a slab, namely, with fields defined on M in R^(3+1), such that M = {(x0, ..., x3)|0 <= x3 <= epsilon}, and bag-like boundary conditions on…
We propose the evanescent-mode-sensing methods to probe the electrodynamics (QED) vacuum polarization. From our methods, high-sensitivity can be achieved even though the external field is much smaller than the Schwinger critical field and…
The worldline formalism has previously been used for deriving compact master formulas for the one-loop N-photon amplitudes in both scalar and spinor QED, and in the vacuum as well as in a constant external field. For scalar QED, there is…
We evaluate one-loop effects for $QED_{4+1}$ compactified to ${\bf R}^4 \times S^1$, in a non-trivial vacuum for the gauge field, such that a non-vanishing magnetic flux is encircled along the extra dimension. We obtain the vacuum…
In continuation to our earlier work, in which the structure of the vacuum polarisation tensor in a medium was analysed in presence of a background electro-magnetic field, we discuss the absorptive part of the vacuum polarization tensor.…
A calculation of the QED vacuum polarization potential in the Coulomb field of a pointlike nucleus was presented in an earlier publication by the author and his collaborators. Corrections up to order $\alpha^2 (Z\alpha)^7$ were evaluated,…