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pro vyhledávání: '"MacCallum, M. A. H."'
Autor:
MacCallum, M. A. H.
It is shown that in many cases local null rotation invariance of the curvature and its first derivatives is sufficient to ensure there is an isometry group G with dimension at least 3 acting on (a neighbourhood of) the spacetime and containing a null
Externí odkaz:
http://arxiv.org/abs/2106.01213
Autor:
MacCallum, M. A. H.
Conditions are found which ensure that local boost invariance (LBI), invariance under a linear boost isotropy, implies local boost symmetry (LBS), i.e. the existence of a local group of motions such that for every point $P$ in a neighbourhood there i
Externí odkaz:
http://arxiv.org/abs/2104.11913
Autor:
MacCallum, M. A. H.
The weakest known criterion for local rotational symmetry (LRS) in spacetimes of Petrov type D is due to Goode and Wainwright (1986). Here it is shown, using methods related to the Cartan-Karlhede procedure, to be equivalent to local spatial rotation
Externí odkaz:
http://arxiv.org/abs/2104.11297
Autor:
MacCallum, M. A. H.
Publikováno v:
Carg\`ese Lectures in Physics, vol.6, ed. E. Schatzman, pages 61-174. Gordon and Breach, New York (1973)
(There is no original abstract.) These are lecture notes from a 1971 summer school surveying the then known cosmological models in particular the properties of Bianchi cosmologies, and giving a pedagogical introduction to groups of isometries in spac
Externí odkaz:
http://arxiv.org/abs/2001.11387
Autor:
McNutt, D. D., MacCallum, M. A. H., Gregoris, D., Forget, A., Coley, A. A., Chavy-Waddy, P. C., Brooks, D.
We show that it is possible to locate the event horizons of a black hole (in arbitrary dimensions) as the zeros of certain Cartan invariants. This approach accounts for the recent results on the detection of stationary horizons using scalar polynomia
Externí odkaz:
http://arxiv.org/abs/1709.03362
Martin David Kruskal was one of the most versatile theoretical physicists of his generation and is distinguished for his enduring work in several different areas, most notably plasma physics, a memorable detour into relativity, and his pioneering wor
Externí odkaz:
http://arxiv.org/abs/1707.00139
Autor:
Akbar, M. M., MacCallum, M. A. H.
An explicit one-parameter Lie point symmetry of the four-dimensional vacuum Einstein equations with two commuting hypersurface-orthogonal Killing vector fields is presented. The parameter takes values over all of the real line and the action of the g
Externí odkaz:
http://arxiv.org/abs/1508.05196
Autor:
Buchert, T., Carfora, M., Ellis, G. F. R., Kolb, E. W., MacCallum, M. A. H., Ostrowski, J. J., Räsänen, S., Roukema, B. F., Andersson, L., Coley, A. A., Wiltshire, D. L.
Publikováno v:
Class. Quantum Grav. 32 (2015) 215021
No. In a number of papers Green and Wald argue that the standard FLRW model approximates our Universe extremely well on all scales, except close to strong field astrophysical objects. In particular, they argue that the effect of inhomogeneities on av
Externí odkaz:
http://arxiv.org/abs/1505.07800
Autor:
MacCallum, M. A. H.
Hubble's announcement of the magnitude-redshift relation \cite{Hub29} brought about a major change in our understanding of the Universe. After tracing the pre-history of Hubble's work, and the hiatus in our understanding which his underestimate of di
Externí odkaz:
http://arxiv.org/abs/1504.03606
Publikováno v:
Class.Quant.Grav.26:215008,2009
The locally rotationally symmetric tilted perfect fluid Bianchi type V cosmological model provides examples of future geodesically complete spacetimes that admit a `kinematic singularity' at which the fluid congruence is inextendible but all frame co
Externí odkaz:
http://arxiv.org/abs/0907.1620