caa a22 4500 463195787 CHVBK 20180406164922.0 cr unu---uuuuu 170326e20070901xx s 000 0 eng 10.1007/s10773-007-9347-9 doi (NATIONALLICENCE)springer-10.1007/s10773-007-9347-9 Carter Brandon LuTh, Observatoire de Paris-Meudon, 92195, Meudon, France aut Poly-Essential and General Hyperelastic World (Brane) Models [Elektronische Daten] [Brandon Carter] This article provides a unified treatment of an extensive category of non-linear classical field models whereby the universe is represented (perhaps as a brane in a higher dimensional background) in terms of a structure of a mathematically convenient type describable as hyperelastic, for which a complete set of equations of motion is provided just by the energy-momentum conservation law. Particular cases include those of a perfect fluid in quintessential backgrounds of various kinds, as well as models of the elastic solid kind that has been proposed to account for cosmic acceleration. It is shown how an appropriately generalised Hadamard operator can be used to construct a symplectic structure that controles the evolution of small perturbations, and that provides a characteristic equation governing the propagation of weak discontinuities of diverse (extrinsic and extrinsic) kinds. The special case of a poly-essential model—the k-essential analogue of an ordinary polytropic fluid—is examined and shown to be well behaved (like the fluid) only if the pressure to density ratio w is positive. Springer Science+Business Media, LLC, 2007 International Journal of Theoretical Physics Springer US; http://www.springer-ny.com 46/9(2007-09-01), 2299-2312 0020-7748 46:9<2299 2007 46 10773 https://doi.org/10.1007/s10773-007-9347-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10773-007-9347-9 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Carter Brandon LuTh, Observatoire de Paris-Meudon, 92195, Meudon, France aut NATIONALLICENCE 773 0- International Journal of Theoretical Physics Springer US; http://www.springer-ny.com 46/9(2007-09-01), 2299-2312 0020-7748 46:9<2299 2007 46 10773 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer