Mètrica d'Alcubierre: diferència entre les revisions

D <math>g</math> is the determinant of the metric [[tensor]]. Thus, as the energy density is negative, one needs [[exotic matter]] to travel faster than the speed of light'.<ref name="Christopher Pike" /> The existence of exotic matter is not theoretically ruled out, the [[Casimir effect]] and the [[Accelerating Universe]] both lends support to the proposed existence of such matter. However, generating enough exotic matter and sustaining it to perform feats such as faster-than-light travel (and also to keep open the 'throat' of a [[wormhole]]) is thought to be impractical. Low has argued that within the context of general relativity, it is impossible to construct a warp drive in the absence of exotic matter.<ref>{{cite journal | autor=Low, Robert J. | title=Speed Limits in General Relativity | pub-periódica=Class. Quant. Grav. | año=1999 | volumen=16 | páginas=543-549}} See also the {{Cita web | title=eprint version | work=arXiv | url=http://www.arxiv.org/abs/gr-qc/9812067 | accessmonthday=30 June | añoacceso=2005}}</ref> It is generally believed that a consistent theory of [[quantum gravity]] will resolve such issues once and for all.

* {{ref-publicació|cognom=Hiscock| nom=William A.|títol= Quantum effects in the Alcubierre warp drive spacetime | publicació= Class. Quant. Grav. | any=1997 | volum=14 | pàgina.=L183-L188 | url= http://www.arxiv.org/abs/gr-qc/9707024 | accessmonthday=23 June }} {{en}}

* {{ref-publicació| autor=L. H. Ford and T. A. Roman| títol=Quantum field theory constrains traversable wormhole geometries| publicació=Physical Review D| any=1996 | pàgina=5496}} v.t. also the {{ref-web| títol=eprint | obra=arXiv | url=http://www.arxiv.org/abs/gr-qc/9510071 }} {{en}}

* T. S. Taylor, T. C. Powell, "Current Status of Metric Engineering with Implications for the Warp Drive," AIAA-2003-4991 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, Huntsville, Alabama, July 20-23, 2003 {{en}}