scholarly journals More about scalar gravity

2016 ◽  
Vol 93 (12) ◽  
Author(s):  
E. Bittencourt ◽  
U. Moschella ◽  
M. Novello ◽  
J. D. Toniato
Keyword(s):  
2000 ◽  
Vol 479 (4) ◽  
pp. 411-420 ◽  
Author(s):  
J.A. Helayel-Neto ◽  
A. Penna-Firme ◽  
I.L. Shapiro

2019 ◽  
Vol 99 (6) ◽  
Author(s):  
Alexander Ganz ◽  
Purnendu Karmakar ◽  
Sabino Matarrese ◽  
Dmitri Sorokin

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Anna Nakonieczna ◽  
Łukasz Nakonieczny

AbstractThe objective of the paper was to examine gravitational evolutions in the Higgs-dark matter sector toy model. The real part of the Higgs doublet was modelled by a neutral scalar. Two dark matter candidates introduced were the dark photon and a charged complex scalar. Non-minimal couplings of both scalars to gravity were included. The coupling channels between the ordinary and dark matter sectors were kinetic mixing between the electromagnetic and dark U(1) fields and the Higgs portal coupling among the scalars. The structures of emerging singular spacetimes were either of Schwarzschild or Reissner–Nordström types. The non-minimal scalar–gravity couplings led to an appearance of timelike portions of apparent horizons where they transform from spacelike to null. The features of dynamical black holes were described as functions of the model parameters. The black holes formed later and their radii and masses were smaller as the mass parameter of the complex scalar increased. The dependencies on the coupling of the Higgs field to gravity exhibited extrema, which were a maximum for the time of the black holes formation and minima in the cases of their radii and masses. A set of quantities associated with an observer moving with the evolving matter was proposed. The energy density, radial pressure and pressure anisotropy within dynamical spacetimes get bigger as the singularity is approached. The increase is more considerable in the Reissner–Nordström spacetimes. The apparent horizon local temperature changes monotonically in the minimally coupled case and non-monotonically when non-minimal scalar–gravity couplings are involved.


1998 ◽  
Vol 249 (5-6) ◽  
pp. 383-388 ◽  
Author(s):  
Eric W. Hirschmann ◽  
Anzhong Wang

2002 ◽  
Vol 11 (10) ◽  
pp. 1531-1536
Author(s):  
L. RAUL ABRAMO ◽  
LEON BRENIG ◽  
EDGARD GUNZIG

In Einstein's gravity, non-minimal coupling of a scalar field to the scalar curvature leads to a paradoxical situation. On the one hand, it opens the way to qualitatively new cosmological dynamics. On the other hand, there are sectors of non-minimally coupled scalar-gravity theories for which the Einstein–Hilbert action reverses its sign, which seems to indicate that the whole system is unstable. We show how conformal coupling bypasses this problem. Due to a subtle interplay between gravity and the scalar field, classical and quantum stability are guaranteed globally. This liberates conformal coupling from a serious obstacle. Inflationary solutions in the new sector are also presented, which are validated by current observations.


1996 ◽  
Vol 54 (2) ◽  
pp. 1474-1491 ◽  
Author(s):  
Thibault Damour ◽  
Gilles Esposito-Farèse
Keyword(s):  

2012 ◽  
Vol 85 (8) ◽  
Author(s):  
Mariano Cadoni ◽  
Matteo Serra ◽  
Salvatore Mignemi

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