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A. Soleiman

Publications and source records attributed to A. Soleiman.

At least 19 recordsLinked to original sources

Golden Finsler Geometry: Local Properties and Global Deformations

We introduce the concept of a golden Finsler structure on a finite-dimensional smooth manifold $M$ and investigate it from both local (coordinate-based) and global (coordinate-free) perspectives. Locally, we explicitly compute the fundamental metric tensor, establish the positive definiteness condition, and derive the geodesic spray coefficients. Furthermore, we investigate the projective flatness of the golden $(\alpha, \beta)$-metric and prove the non-existence of almost rational golden $(\alpha, \beta)$-metrics. Globally, we define the golden Finsler change $\widetilde{F}$ of a base Finsler metric $F$ and examine its geometric properties utilizing a special concurrent $\pi$-vector field. We explicitly determine how fundamental non-linear structures, including the Barthel and Berwald connections, transform under this change. Finally, we prove that $\widetilde{F}$ and $F$ cannot be projectively related.

math.DG

On Generalized Matsumoto Metrics with a Special $\pi$-form

We explore a generalization of Matsumoto metric intrinsically. Given a Finsler manifold $(M,F)$ which admits a concurrent $\pi$-vector field $\overline{\varphi}$, we consider the change $\widehat{F}(x,y)=\frac {F^2 (x,y)} {F(x,y)-\Phi(x,y)}$, where $\Phi$ is the associated concurrent $\pi$-form with $F(x,y) > \Phi(x,y)$ for all $(x,y) \in \T M$. We find the condition under which the generalized $\phi$-Matsumoto metric $\widehat{F}$ is a Finsler metric. Moreover, the relations between the associated Finslerian geometric objects of $\widehat{F}$ and $F$ are obtained, namely, the relations between angular metric tensors, metric tensors, Cartan torsions, geodesic sprays, Barthel connections (along with its curvature) and Berwald connections. Further, we prove that the Finsler metrics $F$ and $\widehat{F}$ can never be projectively related. Also, a condition for the $\pi$-vector field $\overline{\varphi}$ to be concurrent with respect to $\widehat{F}$ is acquired. Moreover, an example of a rational Finsler metric admitting a concurrent $\pi$-vector field together with the associated change $\widehat{F}$ is provided. Finally, we find the conditions that preserve the almost rationality property of a Finsler metric $F$ under the $\phi$-Matsumoto change.

math.DG

The existence and uniqueness of Hashiguchi connection in KG-approach

In this study, we treat intrinsic Finsler geometry using the Klein-Grifone approach (KG-approach). A uniqueness and existence theorem for the Hashiguchi connection on a Finsler manifold is investigated intrinsically (in coordinate-free fashion). Calculations are made for the Hashiguchi connection's torsion and curvature tensors. Some properties are examined, together with the Bianchi identities of the associated curvature and torsion tensors. An overview of the four fundamental linear connections in Finsler geometry in the KG-approach is provided globally for comparison's sake and completeness.

math.DG

A Concurrent Generalized Kropina Change

This paper investigates a generalized Kropina metric featuring a specific $\pi$-form. Start with a Finsler manifold $(M,F)$ admits a concurrent $\pi$-vector field $\overline{\varphi}$, then, examine the $\phi$-concurrent generalized Kropina change defined by $\widehat{F}=\frac{F^{m+1}}{\Phi^{m}},\,\, \Phi^{m}>0$, where $\Phi$ represents the corresponding $1$-form. We investigate the fundamental geometric objects associated with $\widehat{F}$ in an intrinsic manner after adopting this modification and present an example of a Finsler metric that admits a concurrent vector field along with $\widehat{F}$. Also, we prove that the geodesic sprays of $F$ and $\widehat{F}$ can never be projectively related. Moreover, we show $\overline{\varphi}$ is not concurrent with respect to $\widehat{F}$. Eventhough, we give a sufficient condition for $\overline{\varphi}$ to be concurrent with respect to $\widehat{F}$. Finally, we prove that the $\phi$-concurrent generalized Kropina change ($F \longrightarrow \widehat{F}$) preserves the almost rational property of the initial Finsler metric ${F}$.

math.DG

On the covariant coefficients of geodesic sprays on Finsler manifolds

For a Finsler metric $F$, we introduce the notion of $F$-covariant coefficients $H_i$ of the geodesic spray of $F$ (Def. 3.1). We study some geometric consequences concerning the objects $H_i$. If the $F$-covariant coefficients $H_i$ are written in the form $H_i={\dot{\partial}}_iH$, for some smooth function $H$ on ${\mathcal T\hspace{-1pt}M}$, positively 3-homogeneous in y, then $H$ is called spray scalar or simply $S$-scalar. We prove that if the $S$-scalar exists, then it is of the form $H=\frac{1}{12}\,y^i\partial_iF^2$ and this expression is unique up to a function of position only. We prove also that on a Finsler maifold $(M,F)$, the $S$-scalar $H$ exists if and only if $(M,F)$ is dually flat. Generally, the $n^3$ functions $H^h_{ij}$ resulting from the $F$-covariant coefficients do not form a linear connection. We find out that in the case of projectively flat metrics, the $n^3$ functions $H^h_{ij}$ are coefficients of a linear connection. We introduce two new special Finsler spaces, namely, the $H$-Berwald and the $H$-Landsberg spaces and show that every $H$-Berwald metric is $H$-Landsbergian but the converse is not necessarily true. Also, we study the $F$-covariant coefficients $H_i$ of projectivly flat and dually flat spherically symmetric Finsler metrics and provide a solution of the "$H$-unicorn" Landsberg problem. Finally, we give some examples of $H$-Berwald and $H$-Landsberg metrics and an example of $H$-Landsberg metric which is not $H$-Berwaldian.

math.DG

Tripathi Connection in Finsler Geometry

Adopting the pullback formalism, a new linear connection in Finsler geometry has been introduced and investigated. Such connection unifies all formerly known Finsler connections and some other connections not introduced so far. Also, our connection is a Finslerian version of the Tripathi connection introduced in Riemannian geometry. The existence and uniqueness of such connection is proved intrinsically. An explicit intrinsic expression relating this connection to Cartan connection is obtained. Some generalized Finsler connections are constructed from Tripathi Finsler connection, by applying the P1-process and C-process introduced by Matsumoto. Finally, under certain conditions, many special Finsler connections are given.

math.DG

Coordinate-free study of Finsler spaces of $H_{p}$-scalar curvature

The aim of the present paper is to provide an \emph{intrinsic} investigation of special Finsler spaces of $H_{p}$-scalar curvature and of $H_{p}\,$-constant curvature. Characterizations of such spaces are shown. Sufficient condition for Finsler space of $H_{p}$-scalar curvature to be of perpendicular scalar curvature is investigated. Necessary and sufficient condition under which a Finsler space of scalar curvature turns into a Finsler space of $H_{p}$-scalar curvature is given. Further, certain conditions under which a Finsler manifolds of $H_{p}$-scalar curvature and of scalar curvature reduce to a Finsler manifold of $H_{p}$-constant curvature are obtained. Finally, various examples are studied and constructed.

math.DG

On Hyper-Generalized Recurrent Finsler Spaces

The aim of the present paper is to investigate new types of recurrence in Finsler geometry, namely, hyper-generalized recurrence and generalized conharmonic recurrence. The properties of such recurrences and their relations to other Finsler recurrences are studied.

math.DG

On Horizontal Recurrent Finsler Connections

In this paper we adopt the pullback approach to global Finsler geometry. We investigate horizontally recurrent Finsler connections. We prove that for each scalar ($π$)1-form $A$, there exists a unique horizontally recurrent Finsler connection whose $h$-recurrence form is $A$. This result generalizes the existence and uniqueness theorem of Cartan connection. We then study some properties of a special kind of horizontally recurrent Finsler connection, which we call special HRF-connection.

math.DG

New Special Finsler Spaces

The pullback approach to global Finsler geometry is adopted. Some new types of special Finsler spaces are introduced and investigated, namely, Ricci, generalized Ricci, projectively recurrent and m-projectively recurrent Finsler spaces. The properties of these special Finsler spaces are studied and the relations between them are singled out.

math.DG

Some Types of Recurrence in Finsler geometry

The pullback approach to global Finsler geometry is adopted. Three classes of recurrence in Finsler geometry are introduced and investigated: simple recurrence, Ricci recurrence and concircular recurrence. Each of these classes consists of four types of recurrence. The interrelationships between the different types of recurrence are studied. The generalized concircular recurrence, as a new concept, is singled out.

math.DG

New Conformal Invariants in Absolute Parallelism Geometry

The aim of the present paper is to investigate conformal changes in absolute parallelism geometry. We find out some new conformal invariants in terms of the Weitzenböck connection and the Levi-Civita connection of an absolute parallelism space.

math.DG

Characterization of Finsler Spaces of Scalar Curvature

The aim of the present paper is to provide an intrinsic investigation of two special Finsler spaces whose defining properties are related to Berwald connection, namely, Finsler space of scalar curvature and of constant curvature. Some characterizations of a Finsler space of scalar curvature are proved. Necessary and sufficient conditions under which a Finsler space of scalar curvature reduces to a Finsler space of constant curvature are investigated.

math.DG

Concircular $π$-Vector Fields and Special Finsler Spaces

The aim of the present paper is to investigate intrinsically the notion of a concircular $π$-vector field in Finsler geometry. This generalizes the concept of a concircular vector field in Riemannian geometry and the concept of a concurrent vector field in Finsler geometry. Some properties of concircular $π$-vector fields are obtained. Different types of recurrence are discussed. The effect of the existence of a concircular $π$-vector field on some important special Finsler spaces is investigated. The whole work is formulated in a coordinate-free form.

math.DG

Nullity distributions associated to Cartan connection

The Klein-Grifone approach to global Finsler geometry is adopted. The nullity distributions of the three curvature tensors of Cartan connection are investigated. Nullity distributions concerning certain relevant special Finsler spaces are considered. Concrete examples are given whenever the situation needs.

math.DG

On Concircularly Recurrent Finsler Manifolds

Two special Finsler spaces have been introduced and investigated, namely $R^h$-recurrent Finsler space and consircularly recurrent Finsler space. The defining properties of these spaces are formulated in terms of the first curvature tensor of Cartan connection. The following three results constitute the main object of the present paper: 1. A concircularly flat Finsler manifold is necessarily of constant curvature (Theorem A); 2. Every $R^h$-recurrent Finsler manifold is concirculaly recurrent with the same recurrence form (Theorem B); 3. Every horizontally integrable concircularly recurrent Finsler manifold is $R^h$-recurrent with the same recurrence form (Theorem C). The whole work is formulated in a coordinate-free form.

math.DG

Concurrent $π$-vector fields and energy beta-change

The present paper deals with an \emph{intrinsic} investigation of the notion of a concurrent $π$-vector field on the pullback bundle of a Finsler manifold $(M,L)$. The effect of the existence of a concurrent $π$-vector field on some important special Finsler spaces is studied. An intrinsic investigation of a particular $β$-change, namely the energy $β$-change ($\widetilde{L}^{2}(x,y)=L^{2}(x,y)+ B^{2}(x,y) with \ B:=g(\barζ,\barη)$; $\barζ $ being a concurrent $π$-vector field), is established. The relation between the two Barthel connections $Γ$ and $\widetildeΓ$, corresponding to this change, is found. This relation, together with the fact that the Cartan and the Barthel connections have the same horizontal and vertical projectors, enable us to study the energy $β$-change of the fundamental linear connection in Finsler geometry: the Cartan connection, the Berwald connection, the Chern connection and the Hashiguchi connection. Moreover, the change of their curvature tensors is concluded. It should be pointed out that the present work is formulated in a prospective modern coordinate-free form.

math.DG