On the total energy conservation of the Alcubierre spacetime
arXiv:2201.05684 · doi:10.1088/1475-7516/2022/07/030
Abstract
In this article, we consider the Alcubierre spacetime, such a spacetime describes a ``bubble'' that propagates with arbitrary global velocity. This setting allows movement at a speed greater than that of light. There are some known problems with this metric, e.g., the source's negative energy and the violation of the source's energy conservation when the bubble accelerates. We address these two issues within the realm of the Teleparallel Equivalent of General Relativity (TEGR). The energy conservation problem can be solved when considering the energy of the gravitational field itself. The total energy of the spacetime, gravitational plus source, is conserved even in accelerated motion. We explicitly show the dependence of energy and gravitational energy flux on the frame of reference, one adapted to a static observer and the other to a free-falling one in the same coordinate system. Addressing the problem of energy negativity of the source, we find that a static observer measures positive energy of the source, while an Eulerian observer measures a negative one. Thus, we surmise that negative energy may be a reference problem.
25 pages, 11 figures
References in corpus (8)
- The teleparallel equivalent of general relativity
- On reference frames in spacetime and gravitational energy in freely falling frames
- Generic warp drives violate the null energy condition
- Introducing Physical Warp Drives
- On Conserved Quantities for the Schwarzschild Black Hole in Teleparallel Gravity
- Positive Energy Warp Drive from Hidden Geometric Structures
- Curvature Invariants for the Alcubierre and Natário Warp Drives
- Electrodynamics in accelerated frames revisited