Causal structure in the scalar–tensor theory with field derivative coupling to the Einstein tensor
We investigate the causal structure in the scalar–tensor theory with the field derivative coupling to the Einstein tensor, which is a class of the Horndeski theory in the four-dimensional spacetime. We show that in general the characteristic hypersurface is non-null, which admits the superluminal pr...
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| Format: | Article |
| Language: | English |
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Elsevier
2015-04-01
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| Series: | Physics Letters B |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0370269315001550 |
| _version_ | 1811222876773154816 |
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| author | Masato Minamitsuji |
| author_facet | Masato Minamitsuji |
| author_sort | Masato Minamitsuji |
| collection | DOAJ |
| description | We investigate the causal structure in the scalar–tensor theory with the field derivative coupling to the Einstein tensor, which is a class of the Horndeski theory in the four-dimensional spacetime. We show that in general the characteristic hypersurface is non-null, which admits the superluminal propagations. We also derive the conditions that the characteristic hypersurface becomes null and show that a Killing horizon can be the causal edge for all the propagating degrees of freedom, if the additional conditions for the scalar field are satisfied. Finally, we find the position of the characteristic hypersurface in the dynamical spacetime with the maximally symmetric space, and that the fastest propagation can be superluminal, especially if the coupling constant becomes positive. We also argue that the superluminality itself may not lead to the acausality of the theory. Keywords: Modified theories of gravity |
| first_indexed | 2024-04-12T08:23:11Z |
| format | Article |
| id | doaj.art-8b6927ce326f44d782cef0ee91bfcd3c |
| institution | Directory Open Access Journal |
| issn | 0370-2693 |
| language | English |
| last_indexed | 2024-04-12T08:23:11Z |
| publishDate | 2015-04-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Physics Letters B |
| spelling | doaj.art-8b6927ce326f44d782cef0ee91bfcd3c2022-12-22T03:40:30ZengElsevierPhysics Letters B0370-26932015-04-01743272278Causal structure in the scalar–tensor theory with field derivative coupling to the Einstein tensorMasato Minamitsuji0Centro Multidisciplinar de Astrofisica – CENTRA, Instituto Superior Tecnico – IST, Universidade de Lisboa – UL, Avenida Rovisco Pais 1, 1049-001, PortugalWe investigate the causal structure in the scalar–tensor theory with the field derivative coupling to the Einstein tensor, which is a class of the Horndeski theory in the four-dimensional spacetime. We show that in general the characteristic hypersurface is non-null, which admits the superluminal propagations. We also derive the conditions that the characteristic hypersurface becomes null and show that a Killing horizon can be the causal edge for all the propagating degrees of freedom, if the additional conditions for the scalar field are satisfied. Finally, we find the position of the characteristic hypersurface in the dynamical spacetime with the maximally symmetric space, and that the fastest propagation can be superluminal, especially if the coupling constant becomes positive. We also argue that the superluminality itself may not lead to the acausality of the theory. Keywords: Modified theories of gravityhttp://www.sciencedirect.com/science/article/pii/S0370269315001550 |
| spellingShingle | Masato Minamitsuji Causal structure in the scalar–tensor theory with field derivative coupling to the Einstein tensor Physics Letters B |
| title | Causal structure in the scalar–tensor theory with field derivative coupling to the Einstein tensor |
| title_full | Causal structure in the scalar–tensor theory with field derivative coupling to the Einstein tensor |
| title_fullStr | Causal structure in the scalar–tensor theory with field derivative coupling to the Einstein tensor |
| title_full_unstemmed | Causal structure in the scalar–tensor theory with field derivative coupling to the Einstein tensor |
| title_short | Causal structure in the scalar–tensor theory with field derivative coupling to the Einstein tensor |
| title_sort | causal structure in the scalar tensor theory with field derivative coupling to the einstein tensor |
| url | http://www.sciencedirect.com/science/article/pii/S0370269315001550 |
| work_keys_str_mv | AT masatominamitsuji causalstructureinthescalartensortheorywithfieldderivativecouplingtotheeinsteintensor |