Broken Scale Invariance, Gravity Mass, and Dark Energy inModified Einstein Gravity with Two Measure Finsler like Variables

Stavrinos, P. C.; Vacaru, Sergiu I.

doi:10.3390/universe7040089

Cited by 12 publications

(7 citation statements)

References 79 publications

(422 reference statements)

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“…Finsler and Finsler-like geometries, which are metric generalizations of Riemannian geometry and depend on location, velocity/momentum/scalar coordinates, are potential metric geometries that can intrinsically explain the motion. These dynamic geometries can explain locally anisotropic phenomena, Lorentz violations, field equations, FRW and Raychaudhuri equations, geodesics, and effects of dark matter and dark energy [13,[49][50][51][52][53][54][55], among other things. Taking this approach, one can interpret the gravitational field as a metric of a generalized space-time and see how the field creates a force that constrains motion.…”

Section: Jcap04(2024)061mentioning

confidence: 99%

Black hole solutions with constant Ricci scalar in a model of Finsler gravity

Nekouee,

Narasimhamurthy,

Pacif

2024

J. Cosmol. Astropart. Phys.

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Ricci scalar being zero is equivalent to the vacuum field equation in Finsler space-time. The Schwarzschild metric can be concluded from the field equation's solution if the space-time conserves spherical symmetry. This research aims to investigate Finslerian Schwarzschild-de Sitter space-time. Recent studies based on Finslerian space-time geometric models are becoming more prevalent because the local anisotropic structure of space-time influences the gravitational field and gives rise to modified cosmological relations. We suggest a gravitational field equation with a non-zero cosmological constant in Finslerian geometry and apprehend that the presented Finslerian gravitational field equation corresponds to the non-zero Ricci scalar. In Finsler geometry, the peer of spherical symmetry is the Finslerian sphere. Assuming space-time to conserve the “Finslerian sphere” symmetry, the counterpart of the Riemannian sphere (Finslerian sphere) must have a constant flag curvature (λ). It is demonstrated that the Finslerian covariant derivative of the geometric part of the gravitational field equation is preserved under a condition using the Chern connection. According to the string theory, string clouds can be defined as a pool of strings made due to symmetry breaking in the universe's early stages. We find that for λ ≠ 1, this solution resembles a black hole surrounded by a cloud of strings. Furthermore, we investigate null and time-like geodesics for λ = 1. In this regard, the photon geodesics are obtained that are the closest paths to the photon sphere of the first photons visible at the black hole shadow limit. Also, circular orbit conditions are obtained for the effective potential.

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Section: Jcap04(2024)061mentioning

confidence: 99%

Black hole solutions with constant Ricci scalar in a model of Finsler gravity

Nekouee,

Narasimhamurthy,

Pacif

2024

J. Cosmol. Astropart. Phys.

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“…In addition, we use the following definitions for the torsion components: are torsion components, where L α βν is defined in (19). From the form of (10) it follows that √ |G| = √ −g √ −v, with g, v the determinants of the metrics g μν , v αβ respectively.…”

Section: Conclusion and Future Challengesmentioning

confidence: 99%

“…Candidate metric geometries that can intrinsically describe the motion a e-mail: manoliskapsabelis@yahoo.gr b e-mail: kevrekid@math.umass.edu c e-mail: pstavrin@math.uoa.gr d e-mail: alktrian@phys.uoa.gr (corresponding author) are the Finsler and Finsler-like geometries which constitute metrical generalizations of Riemannian geometry and depend on position and velocity/momentum/scalar coordinates. These are dynamic geometries that can describe locally anisotropic phenomena and Lorentz violations [5][6][7][8][9][10][11][12][13][14][15] as well as with field equations, FRW and Raychaudhuri equations, geodesics, dark matter and dark energy effects [16][17][18][19][20][21]. By considering this approach, the gravitational field is interpreted as the metric of a generalized spacetime and constitutes a force-field which contains the motion.…”

Section: Introductionmentioning

confidence: 99%

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Schwarzschild–Finsler–Randers spacetime: geodesics, dynamical analysis and deflection angle

2022

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In this work, we extend the study of Schwarzschi ld–Finsler–Randers (SFR) spacetime previously investigated by a subset of the present authors (Triantafyllopoulos et al. in Eur Phys J C 80(12):1200, 2020; Kapsabelis et al. in Eur Phys J C 81(11):990, 2021). We will examine the dynamical analysis of geodesics which provides the derivation of the energy and the angular momentum of a particle moving along a geodesic of SFR spacetime. This study allows us to compare our model with the corresponding of general relativity (GR). In addition, the effective potential of SFR model is examined and it is compared with the effective potential of GR. The phase portraits generated by these effective potentials are also compared. Finally we deal with the derivation of the deflection angle of the SFR spacetime and we find that there is a small perturbation from the deflection angle of GR. We also derive an interesting relation between the deflection angles of the SFR model and the corresponding result in the work of Shapiro et al. (Phys Rev Lett 92(12):121101, 2004). These small differences are attributed to the anisotropic metric structure of the model and especially to a Randers term which provides a small deviation from GR.

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“…In the holonomic base limit, = 0, the generalised curvature tensor (28) reduces to the standard Riemann tensor.…”

Section: A Basic Structure Of the Lorentz Scalar Tensor Fiber Bundlementioning

confidence: 99%

Dark Gravitational Sectors on a Generalized Scalar-Tensor Vector Bundle Model and Cosmological Applications

Konitopoulos,

Saridakis,

Stavrinos

et al. 2021

Preprint

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In this work we present the foundations of generalized scalar-tensor theories arising from vector bundle constructions, and we study the kinematic, dynamical and cosmological consequences. In particular, over a pseudo-Riemannian space-time base manifold, we define a fiber structure with two scalar fields. The resulting space is a 6-dimensional vector bundle endowed with a non-linear connection. We provide the form of the geodesics and the Raychaudhuri and general field equations, both in Palatini and metrical method. When applied at a cosmological framework, this novel geometrical structure induces extra terms in the modified Friedmann equations, leading to the appearance of an effective dark energy sector, as well as of an interaction of the dark mater sector with the metric. We show that we can obtain the standard thermal history of the universe, with the sequence of matter and dark-energy epochs, and furthermore the effective dark-energy equation-of-state parameter can lie in the quintessence or phantom regimes, or exhibit the phantom-divide crossing.

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Broken Scale Invariance, Gravity Mass, and Dark Energy inModified Einstein Gravity with Two Measure Finsler like Variables

Cited by 12 publications

References 79 publications

Black hole solutions with constant Ricci scalar in a model of Finsler gravity

Black hole solutions with constant Ricci scalar in a model of Finsler gravity

Schwarzschild–Finsler–Randers spacetime: geodesics, dynamical analysis and deflection angle

Dark Gravitational Sectors on a Generalized Scalar-Tensor Vector Bundle Model and Cosmological Applications

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