scholarly journals Lemaître-Tolman-Bondi static universe in Rastall-like gravity

2020 ◽  
Vol 960 ◽  
pp. 115179
Author(s):  
Zhong-Xi Yu ◽  
Shou-Long Li ◽  
Hao Wei
Keyword(s):  
2007 ◽  
Vol 76 (8) ◽  
Author(s):  
Christian G. Böhmer ◽  
Lukas Hollenstein ◽  
Francisco S. N. Lobo

2013 ◽  
Vol 22 (03) ◽  
pp. 1350012 ◽  
Author(s):  
ABHAS MITRA ◽  
S. BHATTACHARYYA ◽  
NILAY BHATT

We show here that, in the context of Einstein's static universe (ESU), the static cosmological constant Λs = 0. We do so by extending (and not contradicting) the ESU relationship from Λs = 4πρ to Λs = 4πρ = 0, where ρ is the ESU matter density (G = c = 1). This extension follows from the fact that the elements of the spacetime geometry depend on pressure and energy density (ρ). Note in the ΛCDM model, Λ is associated with "Dark Energy (DE)." And, if Λ would be considered as a fundamental constant, it should be zero even for a dynamic universe. In such a case, the observed accelerated expansion could be an artifact of inhomogeneity [D. L. Wiltshire, Phys. Rev. D80 (2009) 123512; E. W. Kolb, Class. Quantum. Grav.28 (2011) 164009] or large peculiar acceleration of the Milky way [C. Tasgas, Phys. Rev. D84 (2011) 063503] or extinction of light of distant supernovae [R. E. Schild and M. Dekker, Astron. Nachr.327 (2006) 729, arXiv:astro-ph/0512236]. The same conclusion has also been obtained in an independent manner [A. Mitra, JCAP03 (2013) 007, doi: 10.1088/1475-7516/2013/03/007].


2002 ◽  
Vol 19 (2) ◽  
pp. 213-221 ◽  
Author(s):  
László Á Gergely ◽  
Roy Maartens

2007 ◽  
Vol 39 (10) ◽  
pp. 1545-1550 ◽  
Author(s):  
Lawrence M. Krauss ◽  
Robert J. Scherrer
Keyword(s):  

1993 ◽  
Vol 02 (02) ◽  
pp. 197-220 ◽  
Author(s):  
D. SAVICKAS

A kinematic expression for the Hubble parameter H is derived which defines it directly in terms of the positions and velocities of all existing mass particles. The derivation is simply based on the concept that the numerical value of H at any instant of time is determined solely by particle positions and velocities that exist at that instant, and it is only indirectly affected by gravity through its actions on particles which change the positions and velocities. This definition of H does not depend on the motion of photons because the motion of a photon in a distant galaxy is determined by H as it moves with a constant velocity in the galaxy’s inertial system at rest in the Hubble drift. The kinematic definition of H is shown to be identical to the conventional expression H=Ṙ/R. Under general conditions it behaves in the usual manner. But in the case when all matter is located in a small volume of space, such as that which could have occurred at the time of origin of the universe, there exists for a brief time a kinematic repulsion which acts in addition to the usual gravitational attraction that is described in the standard solution of relativity. The repulsion could be strong enough to overcome gravitation and cause even a static universe to quickly evolve into an expanding one. In the case of an initially pure and static radiation universe that subsequently expands and creates all matter during the expansion, the kinematically defined H allows matter to be created in clusters at a very early time within a highly uniform background of radiation.


2019 ◽  
Vol 146 ◽  
pp. 103517 ◽  
Author(s):  
Olimjon Eshkobilov ◽  
Emilio Musso ◽  
Lorenzo Nicolodi

2019 ◽  
Vol 340 (9-10) ◽  
pp. 841-846
Author(s):  
Alejndro Cabo Bizet ◽  
Alejandro Cabo Montes de Oca

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