Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
5.0
2.5
Journals
Universe
Special Issues
Geometric Theories of Gravity
share announcement

Geometric Theories of Gravity

A special issue of Universe (ISSN 2218-1997). This special issue belongs to the section "Gravitation".

Deadline for manuscript submissions: 31 December 2026 | Viewed by 4892

Editor

Prof. Dr. László Árpád Gergely

E-Mail Website
Guest Editor
1. Department of Theoretical Physics, University of Szeged, Tisza Lajos krt. 84-86, H-6720 Szeged, Hungary
2. Department of Theoretical Physics, HUN-REN Wigner Research Centre for Physics, Konkoly-Thege Miklós út 29-33, H-1121 Budapest, Hungary
Interests: general relativity; modified gravity; constrained systems; quantization; black hole thermodynamics; accretion; high-energy particle generation; gravitational lensing; gravitational waves; cosmology; dark matter and dark energy models
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The idea for this Special Issue emerged during discussions involving some of the participants of the XII edition of the international Bolyai–Gauss–Lobachevsky conference held in Budapest in late spring 2024. Combining the overlapping scientific interests of these participants, with some of them rekindling their professional contacts after many years at this occasion, resulted in an interesting mixture of results in gravitational physics, obtained both in the framework of general relativity and in modified gravity theories, with applications in astrophysics and cosmology, all of them bearing a special geometric flavor. The Special Issue includes an excerpt of these ideas, but stays also open to contributions from colleagues worldwide on the same line of topics and style.

The papers in this Special Issue will target geometric gravity theories, including general relativity in Riemannian geometry and its reformulations in terms of torsion or nonmetricity variables. These theories are frequently extended in various and nonequivalent ways, with the hope to model dark matter and dark energy and also to provide low-energy models for quantum gravity. This Special Issue also invites extensions towards Finslerian geometric approaches and other modifications of gravitational theories with the inclusion of new fields. Such approaches can provide new perspectives on gravitational physics and cosmology, mimic inflation and late time acceleration, lead to a deeper understanding of the evolution and dynamics of cosmic structures, and also provide ways to confirm or falsify them through predictions on compact stars and their structure, as well as the properties of black holes, their environments, and gravitational waves.

Prof. Dr. László Árpád Gergely
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-anonymized peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Universe is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • spacetime
  • general relativity and its geometric reformulations
  • modified gravity: formal aspects and applications
  • perturbations and gravitational waves
  • cosmology, dark matter, and dark energy models

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • Reprint: MDPI Books provides the opportunity to republish successful Special Issues in book format, both online and in print.

Further information on MDPI's Special Issue policies can be found here.

Published Papers (4 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

10 pages, 270 KB  
Article
On Energy-Momentum Conservation in Non-Minimal Geometry-Matter Coupling Theories
by Gonzalo J. Olmo and Miguel A. S. Pinto
Universe 2025, 11(12), 386; https://doi.org/10.3390/universe11120386 - 24 Nov 2025
Viewed by 717
Abstract
In this work, we discuss the conditions that allow the establishment of an equivalence between f(R,T)=R+λh(T) gravity models and General Relativity (GR) coupled to a modified matter sector. We do [...] Read more.
In this work, we discuss the conditions that allow the establishment of an equivalence between f(R,T)=R+λh(T) gravity models and General Relativity (GR) coupled to a modified matter sector. We do so by considering a D-dimensional spacetime and the matter sector described by nonlinear electrodynamics and/or a scalar field. We find that, for this particular family of models, the action and field equations can indeed be written in terms of a modified matter source within GR. However, when several matter sources are combined, this interpretation is no longer possible if h(T) is a nonlinear function, due to the emergence of crossed terms that mix together the scalar and vector sectors. Full article
(This article belongs to the Special Issue Geometric Theories of Gravity)
25 pages, 770 KB  
Article
Observational Tests of the Conformal Osculating Barthel–Kropina Cosmological Model
by Himanshu Chaudhary, Rattanasak Hama, Tiberiu Harko, Sorin V. Sabau and Shibesh Kumar Jas Pacif
Universe 2025, 11(11), 369; https://doi.org/10.3390/universe11110369 - 7 Nov 2025
Cited by 2 | Viewed by 1295
Abstract
We consider detailed cosmological tests of dark energy models obtained from the general conformal transformation of the Kropina metric, representing an (α,β)-type Finslerian geometry. In particular, we restrict our analysis to the osculating Barthel–Kropina geometry. The Kropina metric [...] Read more.
We consider detailed cosmological tests of dark energy models obtained from the general conformal transformation of the Kropina metric, representing an (α,β)-type Finslerian geometry. In particular, we restrict our analysis to the osculating Barthel–Kropina geometry. The Kropina metric function is defined as the ratio of the square of a Riemannian metric α and of the one-form β. In this framework, we also consider the role of the conformal transformations of the metric, which allows us to introduce a family of conformal Barthel–Kropina theories in an osculating geometry. The models obtained in this way are described by second-order field equations, in the presence of an effective scalar field induced by the conformal factor. The generalized Friedmann equations of the model are obtained by adopting for the Riemannian metric α the Friedmann–Lemaitre–Robertson–Walker representation. In order to close the cosmological field equations, we assume a specific relationship between the component of the one-form β and the conformal factor. With this assumption, the cosmological evolution is determined by the initial conditions of the scalar field and a single free parameter γ of the model. The conformal Barthel–Kropina cosmological models are compared against several observational datasets, including Cosmic Chronometers, Type Ia Supernovae, and Baryon Acoustic Oscillations, using a Markov Chain Monte Carlo (MCMC) analysis, which allows the determination of γ. A comparison with the predictions of standard ΛCDM model is also performed. Our results indicate that the conformal osculating Barthel–Kropina model can be considered as a successful, and simple, alternative to standard cosmological models. Full article
(This article belongs to the Special Issue Geometric Theories of Gravity)
►▼ Show Figures

Figure 1

10 pages, 875 KB  
Article
Hidden Momentum and the Absence of the Gravitational Spin Hall Effect in a Uniform Field
by Andrzej Czarnecki and Ting Gao
Universe 2025, 11(11), 365; https://doi.org/10.3390/universe11110365 - 6 Nov 2025
Cited by 1 | Viewed by 678
Abstract
We re-examine the recent claim that a Dirac particle freely falling in a uniform gravitational field exhibits a spin-dependent transverse deflection (gravitational spin Hall effect). Using a circulating mass model, we show that hidden momentum arises in uniform fields when an object carries [...] Read more.
We re-examine the recent claim that a Dirac particle freely falling in a uniform gravitational field exhibits a spin-dependent transverse deflection (gravitational spin Hall effect). Using a circulating mass model, we show that hidden momentum arises in uniform fields when an object carries angular momentum. On the quantum side, we analyze the Dirac Hamiltonian in a uniform potential, construct its Foldy–Wouthuysen form, and evaluate the Heisenberg evolution of spin-polarized Gaussian packets. The state used previously, with ⟨p⟩=0, is not at rest: because canonical and kinetic momenta differ, the packet carries a spin-dependent hidden momentum from t=0. Imposing ⟨x(0)⟩=⟨v(0)⟩=0 requires a compensating spin-dependent ⟨p(0)⟩; with this preparation ⟨x(t)⟩=0 to leading order in the gravitational acceleration g. Generalizing, an exact Foldy–Wouthuysen transformation (linear in g but to all orders in 1/c) shows that spin-dependent transverse motion begins no earlier than at O(g2) for a broad class of wave packets. We conclude that a uniform field does not produce a gravitational spin Hall effect at linear order; the previously reported drift stems from inconsistent initial states and misinterpreting canonical momentum. Full article
(This article belongs to the Special Issue Geometric Theories of Gravity)
►▼ Show Figures

Figure 1

19 pages, 322 KB  
Article
Weak Gravity Limit in Newer General Relativity
by Alexey Golovnev, Sofia Klimova, Alla N. Semenova and Vyacheslav P. Vandeev
Universe 2025, 11(5), 149; https://doi.org/10.3390/universe11050149 - 3 May 2025
Cited by 2 | Viewed by 1243
Abstract
We analyse linearised field equations around the Minkowski metric, with its standard flat parallel transport structure, in models of newer GR, which refers to quadratic actions in terms of a nonmetricity tensor. We show that half of the freedom in choosing the model [...] Read more.
We analyse linearised field equations around the Minkowski metric, with its standard flat parallel transport structure, in models of newer GR, which refers to quadratic actions in terms of a nonmetricity tensor. We show that half of the freedom in choosing the model parameters is immediately fixed by asking for reasonable properties of tensors and vectors, defined with respect to spatial rotations, and we accurately describe the much more complicated sector of scalars. In particular, we show that, from the teleparallel viewpoint, the STEGR model with an additional term of a gradient squared of the metric determinant exhibits one and a half new dynamical modes, and not just one new dynamical mode as it was previously claimed. Full article
(This article belongs to the Special Issue Geometric Theories of Gravity)
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-4
Back to TopTop