Showing papers on "Four-tensor published in 1993"
TL;DR: In this paper, it was shown that the spacetime tangent bundle is complex in the case of Finsler spacetime, provided that the gauge curvature field vanishes, and the conditions for the vanishing of the Nijenhuis tensor in the anholonomic frame adapted to spacetime connection.
Abstract: It is demonstrated that the spacetime tangent bundle, in the case of a Finsler spacetime, is complex, provided that the gauge curvature field vanishes. This is accomplished by determining the conditions for the vanishing of the Nijenhuis tensor in the anholonomic frame adapted to the spacetime connection.
22 citations
Posted Content•
TL;DR: In this paper, it was shown that for a conformally flat spacetime, the radiated energy is the same as for a flat space (i.e., Minkowski space), which is inconsistent with an equation of motion for such particles derived by DeWitt and Brehme and later corrected by Hobbs.
Abstract: Original abstract: Consider the worldline of a charged particle in a static spacetime. Contraction of the time-translation Killing field with the retarded electromagnetic energy-momentum tensor gives a conserved electromagnetic energy vector which can be used to define the radiated electromagnetic energy. This note points out that for a conformally flat spacetime, the radiated energy is the same as for a flat spacetime (i.e. Minkowski space). This appears to be inconsistent with an equation of motion for such particles derived by DeWitt and Brehme and later corrected by Hobbs [End of original abstract]
New abstract: Same as old abstract with last sentence deleted. The body of the paper is the same as previously. A new Appendix 2 has been added discussing implications to the previous arguments of recent work of Sonego (J. Math. Phys. 40 (1999), 3381-3394) and of Quinn and Wald (Phys. Rev. D 60 (1999), gr-qc/9610053).
3 citations
Journal Article•
TL;DR: The Van-der-Waarden form of the Dirac free-field theory in complex Minkowski space is derived by working out a variational principle that involves a manifestly two-spinor Lagrangian density.
Abstract: The equations of motion yielding the Van-der-Waarden form of the Dirac free-field theory in complex Minkowski space are actually derived by working out a variational principle that involves a manifestly two-spinor Lagrangian density. We make use of this Dirac Lagrangian density to build up a suitable defining relation for the energy-momentum tensor of the theory which gives rise at once to a set of essentially equivalent expressions for the tensor. In particular, it is shown that one of the structures arising from our definition coincides with the well-known Penrose expression up to a conventional overall sign. A set of new covariant contour integrals for the corresponding energy momentum four-vector and angular-momentum bivector is exhibited
2 citations
TL;DR: A possible way to obtain the adiabatic regularized quantum stress-energy tensor in a background curved spacetime is developed within the method of path-integral quantization, useful to investigate the back-reaction effects of a quantized field in the early Universe with an inhomogeneity.
Abstract: A possible way to obtain the adiabatic regularized quantum stress-energy tensor in a background curved spacetime is developed within the method of path-integral quantization. As an illustration, we study the mode of a massive scalar field with arbitrary curvature coupling to the inhomogeneous conformally flat spacetime. The results so obtained are useful to investigate the back-reaction effects of a quantized field in the early Universe with an inhomogeneity.
1 citations