https://doi.org/10.1140/epjp/s13360-021-01104-9
Regular Article
Traversable wormholes with vanishing sound speed in f(R) gravity
1
Dipartimento di Fisica “E. Pancini”, Università di Napoli “Federico II”, Via Cinthia, 80126, Napoli, Italy
2
Scuola Superiore Meridionale, Largo S. Marcellino 10, 80138, Napoli, Italy
3
Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Napoli, Via Cinthia, Napoli, Italy
4
Laboratory of Theoretical Cosmology, Tomsk State University of Control Systems and Radioelectronics (TUSUR), Tomsk, Russia
5
Physics Division, University of Camerino, Via Madonna delle Carceri, Camerino, Italy
6
Dipartimento di Matematica, Università di Pisa, Largo Bruno Pontecorvo, Pisa, Italy
7
National Nanotechnology Laboratory of Open Type (NNLOT), Al-Farabi Kazakh National University, Al-Farabi av. 71, 050040, Almaty, Kazakhstan
8
Dipartimento di Matematica e Fisica, Università degli Studi “Roma Tre”, Via della Vasca Navale, Rome, Italy
9
Istituto Nazionale di Fisica Nucleare, Sezione di Frascati, Via Enrico Fermi, Rome, Italy
Received:
27
December
2020
Accepted:
11
January
2021
Published online:
3
February
2021
We derive exact traversable wormhole solutions in the framework of f(R) gravity with no exotic matter and with stable conditions over the geometric fluid entering the throat. For this purpose, we propose power-law f(R) models and two possible approaches for the shape function b(r)/r. The first approach makes use of an inverse power-law function, namely 
. The second one adopts Padé approximants, used to characterize the shape function in a model-independent way. We single out the P(0, 1) approximant where the fluid perturbations are negligible within the throat, if the sound speed vanishes at 
. The former guarantees an overall stability of the geometrical fluid into the wormhole. Finally, we get suitable bounds over the parameters of the model for the above discussed cases. In conclusion, we find that small deviations from general relativity give stable solutions.
© The Author(s) 2021
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