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Soumendu Roy

Publications and source records attributed to Soumendu Roy.

14 recordsLinked to original sources
arXiv2026

Bochner Flatness and Soliton Dynamics in Lorentzian K\"ahler Spacetime Geometry

We study Riemann solitons and $\eta$-hyperbolic Ricci solitons on Bochner-flat Lorentzian K\"ahler spacetime manifolds. Under the Einstein field equations with cosmological constant and perfect fluid assumptions, explicit formulas for the soliton parameter are derived, yielding criteria for shrinking, steady, and expanding behaviors. Several physically relevant models, including dark fluid, stiff matter, dust, and radiation, are analyzed. We show that Bochner-flat Lorentzian K\"ahler spacetimes are Einstein and investigate the resulting geometric and dynamical consequences. In the context of generalized Robertson--Walker spacetimes, we obtain constraints on the warping function and classify soliton solutions. Global properties such as geodesic completeness, singularity formation, and stability are also examined.

math.DG↗
arXiv2026

Existence, Stability, and Geometric Implications of $\ast$-$\eta$-Schouten Solitons on Kenmotsu Manifolds

In this manuscript, we investigate the characterizations of $\ast$-$\eta$-Schouten solitons on a Kenmotsu manifold when the potential vector field is torse-forming. We determine the nature of the soliton and derive the scalar curvature for a Kenmotsu manifold admitting a $\ast$-$\eta$-Schouten soliton. Further, we establish several conditions associated with the $\ast$-$\eta$-Schouten soliton. We also study the characterization of the vector field under the assumption that the manifold satisfies the $\ast$-$\eta$-Schouten soliton equation. Moreover, certain applications of torse-forming vector fields are discussed in the setting of $\ast$-$\eta$-Schouten solitons on Kenmotsu manifolds. In addition, we examine infinitesimal CL-transformations and the Schouten-Van Kampen connection on Kenmotsu manifolds whose metrics admit $\ast$-$\eta$-Schouten solitons. Finally, an example of a 3-dimensional Kenmotsu manifold admitting a $\ast$-$\eta$-Schouten soliton is constructed to verify the obtained results.

math.DG↗
arXiv2026

Characterizations of $\ast$-Ricci-Bourguignon solitons on Kenmotsu manifolds

In this paper, we have found some features of $\ast$- Ricci Bourguignon Soliton on Kenmotsu manifold. We estimated the conditions for $\ast$-Ricci Bourguignon on Kenmotsu manifold to be compressing, balancing or enlarging accordingly. We have found some curvature properties of Kenmotsu manifold admitting $\ast$-Ricci Bourguignon Soliton. Additionally, we have featured $\ast$-Ricci Bourguignon on Kenmotsu manifold with torse-forming vector field. Finally, we proved an example of $5$-dimensional Kenmotsu manifold on $\ast$-Ricci Bourguignon Soliton.

math.DG↗
arXiv2026

Kenmotsu Contact Geometry Through the Lens of $\ast-\boldsymbol{\kappa}$-Ricci-Bourguignon Almost Solitons

This paper focuses on the study of the newly introduced $\ast-\boldsymbol{\kappa}$-Ricci-Bourguignon almost soliton pertaining to Kenmotsu structure manifolds. Our analysis concerns the characteristics of this soliton and derive the scalar curvature for a Kenmotsu manifold admitting such a structure. Further, we formulate the corresponding vector fields under the assumption that the manifold supports a $\ast-\boldsymbol{\kappa}-$Ricci-Bourguignon soliton. Additionally, we explore applications involving torse-forming vector fields within the framework of the $\ast-\boldsymbol{\kappa}-$Ricci-Bourguignon almost soliton on Kenmotsu structure manifolds. To support the theoretical findings, we provide a concrete illustration belonging to a $\ast-\boldsymbol{\kappa}-$Ricci-Bourguignon almost soliton in a 5D Kenmotsu structure manifold.

math.DG↗
arXiv2024

$\ast$-conformal Einstein solitons on N(k)-contact metric manifolds

The main goal of this paper is devoted to N(k)-contact metric manifolds admitting $\ast$-conformal Einstein soliton and also $\ast$-conformal gradient Einstein soliton. In this settings the nature of the manifold, and the potential vector field, potential function of solitons are characterized, and conditions for the $\ast$-conformal Einstein soliton to be expanding, steady, or shrinking are also given. Furthermore, the nature of the potential vector field is evolved when the metric g of N(k)-contact metric manifold satisfies $\ast$-conformal gradient Einstein soliton. Finally, an illustrative example of a N(k)-contact metric manifold is discussed to verify our findings.

math.DG↗
arXiv2021

Geometry of $*$-$k$-Ricci-Yamabe soliton and gradient $*$-$k$-Ricci-Yamabe soliton on Kenmotsu manifolds

The goal of the current paper is to characterize $*$-$k$-Ricci-Yamabe soliton within the framework on Kenmotsu manifolds. Here, we have shown the nature of the soliton and find the scalar curvature when the manifold admitting $*$-$k$-Ricci-Yamabe soliton on Kenmotsu manifold. Next, we have evolved the characterization of the vector field when the manifold satisfies $*$-$k$-Ricci-Yamabe soliton. Also we have embellished some applications of vector field as torse-forming in terms of $*$-$k$-Ricci-Yamabe soliton on Kenmotsu manifold. Then, we have studied gradient $\ast$-$\eta$-Einstein soliton to yield the nature of Riemannian curvature tensor. We have developed an example of $*$-$k$-Ricci-Yamabe soliton on 5-dimensional Kenmotsu manifold to prove our findings.

math.DG↗
arXiv2021

$\ast$-$η$-Ricci-Yamabe solitons on $α$-Cosymplectic manifolds with a quarter-symmetric metric connection

The goal of the present paper is to deliberate certain types of metric such as $*$-$η$-Ricci-Yamabe soliton on $α$-Cosymplectic manifolds with respect to quarter-symmetric metric connection. Further, we have proved some curvature properties of $α$-Cosymplectic manifolds admitting quarter-symmetric metric connection. Here, we have shown the characteristics of the soliton when the manifold satisfies quarter-symmetric metric connection on $α$-Cosymplectic manifolds. Later, we have acquired Laplace equation from $*$-$η$-Ricci-Yamabe soliton equation when the potential vector field $ξ$ of the soliton is of gradient type in terms of quarter-symmetric metric connection. Next, we have developed the nature of the soliton when the vector field is conformal killing admitting quarter-symmetric metric connection. Finally, we present an example of a 5-dimensional $α$-cosymplectic metric as a $*$-$η$-Ricci-Yamabe soliton with respect to a quarter-symmetric metric connection to prove our results.

math.DG↗
arXiv2021

Conformal Yamabe soliton and $*$-Yamabe soliton with torse forming potential vector field

The goal of this paper is to study conformal Yamabe soliton and $*$-Yamabe soliton, whose potential vector field is torse forming. Here, we have characterized conformal Yamabe soliton admitting potential vector field as torse forming with respect to Riemannian connection, semi-symmetric metric connection and projective semi-symmetric connection on Riemannian manifold. We have also shown the nature of $*$-Yamabe soliton with torse forming vector field on Riemannian manifold admitting Riemannian connection. Lastly we have developed an example to corroborate some theorems regarding Riemannian connection on Riemannian manifold.

math.DG↗
arXiv2021

Geometrical structure in a perfect fluid spacetime with conformal Ricci-Yamabe soliton

The present paper is to deliberate the geometric composition of a perfect fluid spacetime with torse-forming vector field ξ in connection with conformal Ricci-Yamabe metric and conformal η-Ricci-Yamabe metric. Here we have delineated the conditions for conformal Ricci-Yamabe soliton to be expanding, steady, or shrinking. Later, we have acquired Laplace equation from conformal η-Ricci-Yamabe soliton equation when the potential vector field ξ of the soliton is of gradient type. Lastly, we have designated perfect fluid with Robertson-Walker spacetime and some applications of physics and gravity.

math.DG↗
arXiv2020

Some results on η-Yamabe Solitons in 3-dimensional trans-Sasakian manifold

The object of the present paper is to study some properties of 3-dimensional trans-Sasakian manifold whose metric is η-Yamabe soliton. We have studied here some certain curvature conditions of 3-dimensional trans-Sasakian manifold admitting η-Yamabe soliton. Lastly we construct a 3-dimensional trans-Sasakian manifold satisfying η-Yamabe soliton.

math.DG↗
arXiv2020

A Kenmotsu metric as a conformal $η$-Einstein soliton

The object of the present paper is to study some properties of Kenmotsu manifold whose metric is conformal $η$-Einstein soliton. We have studied some certain properties of Kenmotsu manifold admitting conformal $η$-Einstein soliton. We have also constructed a 3-dimensional Kenmotsu manifold satisfying conformal $η$-Einstein soliton.

math.DG↗
arXiv2019

Yamabe Solitons on (LCS)$_n$-manifolds

The object of the present paper is to study some properties of (LCS)$_n$-manifolds whose metric is Yamabe soliton. We establish some characterization of (LCS)$_n$-manifolds when the soliton becomes steady. Next we have studied some certain curvature conditions of (LCS)$_n$-manifolds admitting Yamabe solitons. Lastly we construct a 3-dimensional (LCS)$_n$-manifold satisfying the results.

math.DG↗
arXiv2019

*-Conformal η-Ricci Soliton on Sasakian manifold

In this paper we study *-Conformal η-Ricci soliton on Sasakian manifolds. Here, we discuss some curvature properties on Sasakian manifold admitting *-Conformal η-Ricci soliton. We obtain some significant results on *-Conformal η-Ricci soliton in Sasakian manifolds satisfying R(ξ,X).S = 0, S(ξ,X).R = 0, {\overline}P(ξ,X).S = 0, where {\overline}P is Pseudo-projective curvature tensor.The conditions for *-Conformal η-Ricci soliton on Φ-conharmonically flat and Φ-projectively flat Sasakian manifolds have been obtained in this article. Lastly we give an example of 5-dimensional Sasakian manifolds satisfying *-Conformal η-Ricci soliton.

math.DG↗