Reconstruction of extended f(P) cubic gravity from other modified gravity models

2021 ◽  
pp. 100926
Author(s):  
Alok Sardar ◽  
Ujjal Debnath
2020 ◽  
Vol 501 (1) ◽  
pp. 254-260
Author(s):  
Ali Rida Khalifeh ◽  
Raul Jimenez

ABSTRACT The discovery of 19 dwarf galaxies without dark matter (DM) provides, counterintuitively, strong support for the ΛCDM standard model of cosmology. Their presence is well accommodated in a scenario where the DM is in the form of cold dark particles. However, it is interesting to explore quantitatively what is needed from modified gravity models to accommodate the presence of these galaxies and what extra degree of freedom is needed in these models. To this end, we derive the dynamics at galaxy scales (Virial theorem) for a general class of modified gravity models. We distinguish between theories that satisfy the Jebsen–Birkhoff theorem, and those that do not. Our aim is to develop tests that can distinguish whether DM is part of the theory of gravity or a particle. The 19 dwarf galaxies discovered provide us with a stringent test for models of modified gravity. Our main finding is that there will always be an extra contribution to the Virial theorem coming from the modification of gravity, even if a certain galaxy shows very small, if not negligible, trace of DM, as has been reported recently. Thus, if these and more galaxies are confirmed as devoid (or negligible) of DM, while other similar galaxies have abundant DM, it seems interesting to find modifications of gravity to describe DM. Our result can be used by future astronomical surveys to put constraints on the parameters of modified gravity models at astrophysical scales where DM is described as such.


2009 ◽  
Vol 80 (10) ◽  
Author(s):  
Lam Hui ◽  
Alberto Nicolis ◽  
Christopher W. Stubbs

Entropy ◽  
2015 ◽  
Vol 17 (12) ◽  
pp. 6643-6662 ◽  
Author(s):  
Aimeric Colléaux ◽  
Sergio Zerbini

2012 ◽  
Vol 55 (12) ◽  
pp. 2244-2258 ◽  
Author(s):  
WenShuai Zhang ◽  
Cheng Cheng ◽  
QingGuo Huang ◽  
Miao Li ◽  
Song Li ◽  
...  

2005 ◽  
Vol 71 (6) ◽  
Author(s):  
Sean M. Carroll ◽  
Antonio De Felice ◽  
Vikram Duvvuri ◽  
Damien A. Easson ◽  
Mark Trodden ◽  
...  

Entropy ◽  
2012 ◽  
Vol 14 (7) ◽  
pp. 1140-1153 ◽  
Author(s):  
Andrey N. Makarenko ◽  
Valery V. Obukhov

Sign in / Sign up

Export Citation Format

Share Document