Wormholes in fractional action cosmology

2017 ◽  
Vol 95 (6) ◽  
pp. 605-609 ◽  
Author(s):  
Rami Ahmad El-Nabulsi
2012 ◽  
Vol 354 ◽  
pp. 012008 ◽  
Author(s):  
Mubasher Jamil ◽  
Muneer A Rashid ◽  
D Momeni ◽  
Olga Razina ◽  
Kuralay Esmakhanova

2013 ◽  
Vol 91 (10) ◽  
pp. 844-849 ◽  
Author(s):  
Antonio Pasqua ◽  
Surajit Chattopadhyay

In this work, we considered an effective scalar field theory described by a Lagrangian with a noncanonical kinetic term, which leads to accelerated expansion in the present Universe and is known as k-essence in the framework of the fractional action cosmology recently introduced by El-Nabulsi. We have chosen a particular ansatz for the scale factor and the scalar field, in which both are described as a power-law of the time, t. We have studied the behavior of some cosmological quantities in other models to obtain some useful information about the model considered. We observed that the equation of state parameter, w, has decreasing behavior and it never crosses the phantom divide line (i.e., w = –1). Studying the statefinder pair {r, s} and {w, w′}, we observed that the model considered is able to obtain the ΛCDM phase of the Universe.


2021 ◽  
pp. 1-5
Author(s):  
Rami Ahmad El-Nabulsi

In this study, we discuss string cosmology with solitonic NS–NS matter, which arises when dilaton coupled p-brane gas dominates the universe and is subject to a fractional action motivated from viscosity dissipative effects occurring in the universe. Exact solutions are found from the stationary conditions of the fractional action. It was observed that the universe is non-singular, undergoing accelerated expansion in time and may not be dominated by dark energy because it is strongly affected by dissipations through the fractional parameter α. The numerical ranges of α were obtained using H(z) at the 1σ level for two independent cases: a vacuum energy dominated energy and a non-dominant vacuum energy universe. Our results are in agreement with astronomical observational limits and support both string cosmology and the fractional action cosmology.


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