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We present new traversable wormhole and non-singular black hole solutions in pure, scale-free $R^2$ gravity. These exotic solutions require no null energy condition violating or "exotic" matter and are supported only by the vacuum of the…

General Relativity and Quantum Cosmology · Physics 2015-09-02 Francis Duplessis , Damien A. Easson

We review recent work on wormhole geometries in the context of modified theories of gravity, in particular, in f(R) gravity and with a nonminimal curvature-matter coupling, and in the recently proposed hybrid metric-Palatini theory. In…

General Relativity and Quantum Cosmology · Physics 2013-10-18 Francisco S. N. Lobo

Wormhole configurations in Einstein's general theory of relativity (GR) require exotic matter sources violating the weak energy condition (WEC). Rastall's theory is a generalization of GR in its matter source considering a nonconserved…

General Relativity and Quantum Cosmology · Physics 2024-01-19 Yaghoub Heydarzade , Maryam Ranjbar

The static spherically symmetric traversable wormholes are analysed in the Einstein- Cartan theory of gravitation. In particular, we computed the torsion tensor for matter fields with different spin S = 0; 1/2; 1; 3/2. Interestingly, only…

General Relativity and Quantum Cosmology · Physics 2018-01-12 Emmanuele Battista , Elisabetta Di Grezia , Mattia Manfredonia , Gennaro Miele

A class of $f(R, T)$ theories extends the Einstein-Hilbert action by incorporating a general function of $R$ and $T$, the Ricci scalar and the trace of the ordinary energy-momentum tensor $T_{\mu\nu}$, respectively, thereby introducing a…

General Relativity and Quantum Cosmology · Physics 2025-07-30 Yaghoub Heydarzade , Maryam Ranjbar

This thesis explores traversable wormhole (WH) solutions within symmetric teleparallel gravity and its extensions, including $f(Q)$ and $f(Q, T)$ gravity. Chapter I reviews WH geometry and properties, general relativity, and modified…

General Relativity and Quantum Cosmology · Physics 2025-05-09 Moreshwar Tayde

Wormhole solutions in a generalized hybrid metric-Palatini matter theory, given by a gravitational Lagrangian $f\left(R,\cal{R}\right)$, where $R$ is the metric Ricci scalar, and $\mathcal{R}$ is a Palatini scalar curvature defined in terms…

General Relativity and Quantum Cosmology · Physics 2018-10-03 João Luís Rosa , José P. S. Lemos , Francisco S. N. Lobo

It is a very well known fact that the energy conditions concerning Lorentzian wormhole (WH) solutions of Einstein equations are violated. Consequently, attempts to avoid the violation of the energy conditions constitutes one of the main…

High Energy Physics - Theory · Physics 2012-08-01 Everton M. C. Abreu , Nélio Sasaki

We present a static, spherically symmetric, traversable wormhole solution to multimetric gravity which is sustained by only non-exotic matter, i.e., matter which satisfies all energy conditions. The possibility of this solution arises from…

General Relativity and Quantum Cosmology · Physics 2014-04-11 Manuel Hohmann

We present here analytical solutions of General Relativity that describe evolving wormholes with a non-constant redshift function. We show that the matter that threads these wormholes is not necessarily exotic. Finally, we investigate some…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Luis A. Anchordoqui , Diego F. Torres , Marta L. Trobo , Santiago E. Perez Bergliaffa

An intriguing solution that appears in General Relativity (GR) but has not been observed so far is the wormhole. This exotic solution describes a topological bridge connecting two distinct universes or two different points in the same…

General Relativity and Quantum Cosmology · Physics 2022-08-08 Zinnat Hassan , G. Mustafa , Joao R. L. Santos , P. K. Sahoo

In the present article we propose a new hybrid shape function for wormhole (WH)s in the modified $f(R,T)$ gravity. The proposed shape function satisfied the conditions of WH geometry. Geometrical behavior of WH solutions are discussed in…

General Relativity and Quantum Cosmology · Physics 2020-05-22 Parbati Sahoo , Sanjay Mandal , P. K. Sahoo

It is known that Lorentzian wormholes must be threaded by matter that violates the null energy condition. We phenomenologically characterize such exotic matter by a general class of microscopic scalar field Lagrangians and formulate the…

General Relativity and Quantum Cosmology · Physics 2014-11-17 C. Armendariz-Picon

We investigate possible manifolds characterizing traversable wormholes in the presence of a scalar field minimally coupled to gravity, which has both kinetic and potential energy. The feature of traversability requires the violation of the…

General Relativity and Quantum Cosmology · Physics 2025-10-31 R. Garattini , A. G. Tzikas

Wormholes are speculative structures linking disparate space-time points. Their geometry can be obtained by solving Einstein equations with tolerating the violation of null energy conditions. Recently, many researchers have studied…

General Relativity and Quantum Cosmology · Physics 2022-03-10 J. Sadeghi , B. Pourhassan , S. Noori Gashti , S. Upadhyay

In this work we demonstrate that wormholes can in principle be naturally created during the cosmological bounce without the need for the exotic matter or any kind of additional modifications of the gravitational sector, apart from the one…

General Relativity and Quantum Cosmology · Physics 2025-02-07 Petar Pavlović , Marko Sossich

To create a static traversable wormhole, exotic matter that meets the Morris-Thorne conditions is required. It is well known that the expectation value of the vacuum stress-energy tensor can violate the null energy condition, and thus has…

General Relativity and Quantum Cosmology · Physics 2026-03-03 Shun Jiang , Jie Jiang

In the present work we search for a new wormhole solution inspired by noncommutative geometry with the additional condition of allowing conformal Killing vectors (CKV). A special aspect of noncommutative geometry is that it replaces…

General Relativity and Quantum Cosmology · Physics 2015-05-15 Farook Rahaman , Sreya Karmakar , Indrani Karar , Saibal Ray

Models of static wormholes within the $f(\textit{R}, \textit{T})$ extended theory of gravity are investigated and, in particular, the family $f(\textit{R}, \textit{T}) = R + \lambda T$, with $T = \rho + P_{r} + 2P_{l}$ being the trace of…

General Relativity and Quantum Cosmology · Physics 2019-09-25 Emilio Elizalde , Martiros Khurshudyan

This paper explores static wormhole solutions in f(Q,T) theory, where Q is the non-metricity and T is the trace of energy-momentum tensor. We derive the field equations that describe gravitational phenomena in the existence of non-metricity…

General Relativity and Quantum Cosmology · Physics 2024-11-07 M. Zeeshan Gul , M. Sharif , Shajee Shahid , Faisal Javed