1. Introduction
Hamilton [
1] originally introduced the concepts of Ricci flow in 1988. It proves that Ricci’s soliton is the solution’s limit for the Ricci flow. Additionally, over the past 20 years, many mathematicians have become interested in geometric flow theory, particularly the Ricci flow.
The family of metrics
on a Riemannian manifold
evolve into the Ricci flow [
1] if
Definition 1 ([
1]).
On the Riemannian manifold, , a Ricci soliton () is a data point obeyingwhere the Ricci tensor is , and is the Lie-derivative across the vector field . Depending on the constant λ, the manifold is called a Ricci shrinker, expander, or stable soliton, whether , , or .The Equation (1) becomeswhere denotes the Hessian operator with respect to g. This indicates that (, is a gradient Ricci soliton . In 2020, Blaga and Carasmareanu [
2] established an inequality for a lower bound of the geometry of metric
g in terms of gradient Ricci soliton
for a smooth function
in ambient space
such as
where
is Ricci tensor,
is the Hessian of a smooth function
on
.
On the other hand, Hayden [
3] deserves recognition for popularizing the understanding of a metric connection on a Riemannian manifold. Several geometers have studied the features of Riemannian manifolds with non-metric and semi-symmetric (symmetric) connections ([
4,
5,
6]). Golab [
7] discussed the fundamental concept of quarter-symmetric linear connection. If a linear connection’s torsion tensor
has the following form, it is considered quarter-symmetric.
where
is a
form,
represents a tensor of type
and
are vector fields on a manifold
. If
, the quarter-symmetric connection simplifies to a semi-symmetric connection.
Therefore, it is possible to operate quarter-symmetric connections as an extension of semi-symmetric metric connections (ssm-connection).
If a Riemannian metric
g exists in
such that
then
is a metric connection; if not, it is non-metric.
In [
8] authors proposed an
-connection in almost contact manifold by the relation
On the contrary, trans-Sasakian manifolds
naturally resulted from Gonzales and Chinae’s category of almost contact metric structures [
9].
is a new type of virtual contact Riemannian manifold that was introduced in 1985 by Oubina [
10].
Sasakian, Sasakian,
Kenmotsu, and Kenmotsu, cosymplectic, structures are examples of trans-Sasakian structures. A class
of Hermitian manifolds that are closely connected to locally conformal Kaehler manifolds appears in the Gray–Hervella classification of nearly Hermitian manifolds [
11]. When the product manifold
belongs to the class
, then an almost contact metric structure is referred to as a
structure [
12]. The class of
structures of type
coincides with the
class.
Integrating intrinsic and extrinsic invariants, which are useful tools for researching submanifolds categorization, is one of the most important problems in submanifold theory.
With the aid of severe inequality, Chen [
13] initiated a new framework in the study of the relationship between intrinsic and extrinsic invariants in the early 1990s, and he also presented a novel tool called
-invariants (for more information, see [
14,
15,
16,
17]). Numerous researchers ([
18,
19,
20,
21,
22,
23,
24,
25,
26,
27], etc.) carried out relevant research from various viewpoints in different spaces.
2. Preliminaries
An
-dimensional manifold
equipped with an almost contact metric structure
can be defined as follows:
is a
tensor field,
is a vector field,
is a 1—form, and
g is a compatible Riemannian metric such that
for all
.
Definition 2 ([
18]).
An almost-contact metric structure on is said to be a structure ifwhere α and β are smooth functions on , and we state that the is of the type. Type structures are cosymplectic, type structures are -Sasakian, and type structures are -Kenmotsu.
In [
28],
is examined, and the following results are obtained:
if
, then in view of (
7) the following holds:
3. Characteristics of Curvatures
In this part, we will discover the link between and , where and are the curvature tensors with respect to the connection and the Levi–Civita connection ∇ on a , respectively.
Furthermore, we shall determine the relationship between and , where is the Ricci tensor with respect to the on and is the Ricci tensor with respect to the ∇ on .
In [
29], Tripathi introduced the subsequent relationship:
where
is
connection. Adopting Definition 2 and (
5), (
6), we gain
With this
-connection, we can now extract the Ricci tensor
and the curvature tensor. Here is the curvature tensor
:
Theorem 1 ([
30]).
Let be a with the connection . Then, the equality is shown for any vector fields u, v, and w on where and are the curvature tensors with respect to the ∇ and , respectively. Theorem 2 ([
30]).
Let be a with the connection . Then, the ensuing equality is given: Based on Theorem 2, we obtain the subsequent outcomes.
Theorem 3 ([
30]).
Let be a with the connection ; then, the Ricci tensor and the scalar curvature with respect to the are obtained as follows:where the Ricci tensor and the scalar curvature concerning the Levi–Civita connection on are denoted by and , respectively. 4. Slant Submanifolds of a Trans-Sasakian Manifold with Connection
Let be a submanifold of a of type. For each non-zero vector U tangent to at any point , , if the slant angle between and is independent of the choice of p, then is said to be slant submanifold. Note that if the slant angle is or , then submanifold becomes Φ-invariant and Φ-anti-invariant, respectively. Proper slant, sometimes known as -slant proper, submanifolds are slant submanifolds that are neither anti-invariant nor invariant.
The following characteristics of slant submanifolds in
hold according to the findings of ([
31,
32]).
Theorem 4 ([
31]).
Let Ξ
be a submanifold of an almost contact metric manifold such that . Then- 1.
Ξ
is slant if and only if there exists a constant such thatIn addition, if the Θ is the slant angle of Ξ, then .
- 2.
, for any .
Theorem 5. Let Ξ
be an m-dimensional Θ
-slant submanifold of a with a connection. Then, the scalar curvature with respect to the connection is given as Proof. In view of (
11) and Theorem 4, after contraction over
u and
v, we turn to (
13). □
Let
be a submanifold of a
with a
connection. Then,
where
and
are the tangential and the normal components of
, respectively. It is noted that
is known as invariant if
F is identically zero (that is,
and anti-invariant if
T is identically zero (that is,
.
Similarly,
where
has tangential and normal components, denoted by
and
, respectively. Furthermore,
represents the submanifold
in
, a local orthonormal frame of the tangent bundle
of
, and
indicates the local orthonormal frame of the normal bundle
of
in
, a local orthonormal frame of the normal bundle
of
in
.
In order to derive the normalized scalar curvature
, we first express the second fundamental form of submanifold
using
.
Find the mean curvature using the equation
Let
for
and
. Next, the mean curvature vector’s squared norm is provided by
and
, the second fundamental form, has the equation
Moreover, the divergence of any vector field
u on
is denoted by
and defined by
where
a local orthonormal tangent frame of the tangent bundle
of
.
The scalar curvature expressed by
Then, considering the Gauss equation and (
13), we obtain
5. Ricci Soliton on Slant Submanifold
To obtain a relationship between the intrinsic and extrinsic invariants, we give the scalar curvature of submanifold of Ricci soliton in this section. Then, to describe such a submanifold , we establish an inequality for the Ricci soliton and gradient Ricci soliton.
Let
be a
-dimensional TSM manifold and
be an isometric immersion from an
m-dimensional Riemannian manifold
into
manifold. Then, the Ricci tensor
can be written as
for any
Now, the previous Lemma marks the start of this section:
Lemma 1. Let be an and let Ξ
be an m-dimensional Θ
-slant submanifold of a -dimensional equipped with a , connection . Then, we have Proof. Since
is a
. Then in view of (
17), one get
where
is a local orthonormal tangent frame of the tangent bundle
of
.
Then, adopting (
15), (
13), (4) and (
18) in (
18) we turn up
Adopting Gauss formula and (
17) in (
19), we obtain
Then, the proof is completed. □
As a consequence of Equation (
18), we articulate the following.
Theorem 6. be a and Ξ be a m-dimensional Θ-slant submanifold of a -dimensional equipped with a -connection admits an with a potential vector field of Ricci soliton. Then the Ricci soliton on Ξ is expanding, steady, and shrinking according as
- 1.
- 2.
,
- 3.
,
respectively.
At this stage, we remember the subsequent lemma from [
33]
Lemma 2. If for are real numbers, thenwith equality holding if and only if Theorem 7. Let be a and let Ξ
be an m-dimensional Θ
-slant submanifold of a -dimensional equipped with a connection . Then, we have Proof. In light of Equation (
18), we show that if
is found, then
is obtained, which gives us (
21). If the equality of (
21) is satisfied, then
M is totally umbilical. □
Now, let the soliton vector field
be of gradient type i.e.,
. Thus, in view of (
3) and (
18), we articulate the following.
Theorem 8. Let be a with a soliton vector field is of gradient type, and let Ξ
be an m-dimensional Θ
-slant submanifold of a -dimensional equipped with a connection . Then, we have Corollary 1. Let be a with a soliton vector field of the gradient type, and let Ξ
be an m-dimensional totally umbilical Θ
-slant submanifold of a -dimensional equipped with a connection . Then, we have Remark 1. For anti-invariant submanifolds of trans-Sasakian manifolds using the quarter symmetric non-metric connection, a slant submanifold reduces to an anti-invariant submanifold when and an invariant submanifold is the result of a slant submanifold when
Next, in light of Theorem 8 and Remark 1, we gain the following outcomes:
Corollary 2. Let be a with a soliton vector field of the gradient type, and let Ξ
be an m-dimensional anti-invariant submanifold of a -dimensional equipped with a connection . Then, we have Corollary 3. Let be a with a soliton vector field is of gradient type, and let Ξ
be an m-dimensional invariant submanifold of a -dimensional equipped with a connection . Then, we have Remark 2. Similarly, because of Corollary 1, we can easily obtain the parallel results for totally umbilical anti-invariant submanifold and a totally umbilical invariant submanifold [34] of a -dimensional equipped with a -connection 6. Application of Theorem 8
Corollary 4. Let be a with a soliton vector field of the gradient type, and let Ξ
be an m-dimensional Θ
-slant submanifold of a -dimensional β- equipped with a connection . Then, we have Corollary 5. Let be a with a soliton vector field is of gradient type and Ξ
be a m-dimensional Θ
-slant submanifold of a -dimensional α-Sasakian manifold equipped with a -connection . Then we have Corollary 6. Let be a with a soliton vector field of the gradient type, and let Ξ
be an m-dimensional Θ
-slant submanifold of a -dimensional cosymplectic manifold equipped with a connection . Then, we have Remark 3. Similarly, given Corollaries 4–6, we can easily obtain the parallel results for anti-invariant submanifold and invariant submanifold of a -dimensional β-Kenmotsu, α-Sasakian and cosympletic manifolds with a connection
Corollary 7. Let be a with a soliton vector field of the gradient type, and let Ξ
be an m-dimensional totally umbilical Θ
-slant submanifold of a -dimensional β- equipped with a -connection . Then, we have Remark 4. In addition, in light of Corollaries 4–7, we can easily obtain the parallel results for totally umbilical anti-invariant submanifolds and totally umbilical invariant submanifolds of a -dimensional β-Kenmotsu and α-Sasakian, and cosympletic manifolds with a connection
7. Solitonic Ineqiality with a Scalar Concircular Field
In this section, we deduced the above inequalities with a scalar concircular field in a -dimensional equipped with a -connection . Thus, we entail the following definition.
Definition 3 ([
35]).
If the scalar field fulfills the equation, it is considered a scalar concircular fieldwhere the Riemannian metric is g and a scalar field is π. Inserting (21) in (
3), we gain an inequality for a lower bound of the geometry of
g in terms of
with a scalar concircular field
in ambient space
such that
Next, in view of Equation (
22) and Theorem 8 we obtain the following:
Corollary 8. Let be a with a scalar concircular field and let Ξ
be a m-dimensional submanifold of a -dimensional equipped with a connection . Then we haveS.No | Submanifold is | Solitonical Inequality |
1 | -slant | |
2 | -slant | |
3 | | |
4 | | |
Remark 5. Moreover, in view of Corollary 8, we can easily obtain the parallel results for totally umbilical anti-invariant submanifold and totally umbilical invariant submanifold of -dimensional β-Kenmotsu, α-Sasakian and cosympletic manifolds with a connection