Late time cosmological evolution of the DBI model with collisional matter

2022 ◽  
Author(s):  
F. Mavoa ◽  
M. Ganiou ◽  
S. Houndjo ◽  
A. D. Kanfon ◽  
I. Salako
Keyword(s):  
Cosmological Evolution ◽  
Late Time

Dynamical system approach to cosmological evolution in modified theories of gravity with coupling between matter and geometry

2020 ◽  
Vol 35 (19) ◽  
pp. 2050154
Author(s):  
Jun Wang ◽  
Kang Liu
Keyword(s):  
Dynamical System ◽  
System Approach ◽  
Cosmic Radiation ◽  
Cosmological Evolution ◽  
Accelerated Expansion ◽  
Modified Theories Of Gravity ◽  
Late Time ◽  
Dynamical System Approach ◽  
Dynamical Approach ◽  
Theories Of Gravity

In this paper, a class of [Formula: see text] gravitational models with coupling between matter and geometry have been studied by a dynamical approach in cosmology. The result shows that both the cosmic radiation dominated era and the late-time cosmic accelerated expansion can be achieved in this class of models. Moreover, the corresponding parameters are constrained as well.

scholarly journals Effect of Fast Scale Factor Fluctuations on Cosmological Evolution

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 164
Author(s):  
Igor I. Smolyaninov
Keyword(s):  
Quantum Fluctuations ◽  
Scale Factor ◽  
Cosmological Evolution ◽  
Accelerated Expansion ◽  
Late Time ◽  
Cosmological Constant Problem ◽  
Friedmann Equations ◽  
Newtonian Dynamics ◽  
Expansion Of The Universe ◽  
The Universe

In this paper, we study the corrections to the Friedmann equations due to fast fluctuations in the universe scale factor. Such fast quantum fluctuations were recently proposed as a potential solution to the cosmological constant problem. They also induce strong changes to the current sign and magnitude of the average cosmological force, thus making them one of the potential probable causes of the modification of Newtonian dynamics in galaxy-scale systems. It appears that quantum fluctuations in the scale factor also modify the Friedmann equations, leading to a considerable modification of cosmological evolution. In particular, they give rise to the late-time accelerated expansion of the universe, and they may also considerably modify the effective universe potential.

scholarly journals Late-time cosmological evolution in degenerate higher-order scalar-tensor models

2020 ◽  
Vol 102 (2) ◽  
Author(s):  
Hamza Boumaza ◽  
David Langlois ◽  
Karim Noui
Keyword(s):  
Higher Order ◽  
Cosmological Evolution ◽  
Late Time ◽  
Tensor Models

Cosmic inflation without inflaton

2019 ◽  
Vol 28 (14) ◽  
pp. 1944008 ◽  
Author(s):  
Gustavo Arciniega ◽  
Pablo Bueno ◽  
Pablo A. Cano ◽  
José D. Edelstein ◽  
Robie A. Hennigar ◽  
...  
Keyword(s):  
Exponential Growth ◽  
Big Bang ◽  
Einstein Gravity ◽  
Scale Factor ◽  
Cosmological Evolution ◽  
Late Time ◽  
Cosmic Inflation ◽  
Well Posed ◽  
Hilbert Action

We propose a novel explanation for universe’s inflationary period. We argue that when the Einstein–Hilbert action is supplemented by an infinite tower of higher-curvature terms — selected order by order by the criterium that they give rise to a well-posed cosmological evolution — the usual Big Bang characteristic of Einstein gravity is replaced by a singularity-free period of exponential growth of the scale factor, which is gracefully connected with standard late-time [Formula: see text]CDM cosmology. No inflaton or any additional fields besides the metric are required.

scholarly journals Dynamics of a scalar field, with a double exponential potential, interacting with dark matter

2015 ◽  
Vol 24 (08) ◽  
pp. 1550068 ◽  
Author(s):  
Vartika Gupta ◽  
Rakesh Kabir ◽  
Amitabha Mukherjee ◽  
Daksh Lohiya
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Scalar Field ◽  
Effective Potential ◽  
Cosmological Evolution ◽  
Late Time ◽  
Exponential Potential ◽  
Double Exponential

We study the interaction between dark matter and dark energy, with dark energy described by a scalar field having a double exponential effective potential. We discover conditions under which such a scalar field driven solution is a late time attractor. We observe a realistic cosmological evolution which consists of sequential stages of dominance of radiation, matter and dark energy, respectively.

scholarly journals Intermediate Inflation or Late Time Acceleration?

2008 ◽  
Vol 2008 ◽  
pp. 1-16 ◽  
Author(s):  
Abhik Kumar Sanyal
Keyword(s):  
Scalar Field ◽  
Power Law ◽  
Cosmological Evolution ◽  
Expansion Rate ◽  
Accelerated Expansion ◽  
Kinetic Term ◽  
Late Time ◽  
Late Time Acceleration ◽  
Cosmic Evolution ◽  
Scaling Solution

The expansion rate of “intermediate inflation” lies between the exponential and power law expansion but corresponding accelerated expansion does not start at the onset of cosmological evolution. Present study of “intermediate inflation” reveals that it admits scaling solution and has got a natural exit form it at a later epoch of cosmic evolution, leading to late time acceleration. The corresponding scalar field responsible for such feature is also found to behave as a tracker field for gravity with canonical kinetic term.

Sign in / Sign up

Export Citation Format

Share Document