Next Article in Journal
Intelligent Computing Collaboration for the Security of the Fog Internet of Things
Previous Article in Journal
Quantum Related-Key Attack Based on Simon’s Algorithm and Its Applications
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Research on the Symmetry of the Hamiltonian System under Generalized Operators

School of Mathematical Sciences, Suzhou University of Science and Technology, Suzhou 215009, China
*
Author to whom correspondence should be addressed.
Symmetry 2023, 15(5), 973; https://doi.org/10.3390/sym15050973
Submission received: 17 March 2023 / Revised: 15 April 2023 / Accepted: 21 April 2023 / Published: 24 April 2023

Abstract

:
Generalized operators have recently been proposed with great potential applications. Here, we present research carried out on Noether figury and perturbation to Noether symmetry for Hamiltonian systems within generalized operators. There are four parts, and each part contains two kinds of generalized operator. Firstly, Hamilton equations are established. Secondly, the Noether symmetry method is used for finding the solutions to the differential equations of motion, and conserved quantities are obtained. Thirdly, perturbation to Noether symmetry and adiabatic invariants are further explored. In the end, two examples are given to illustrate the methods and results.

1. Introduction

In 1788, Lagrange published his famous book Analytical Mechanics, in which he expressed the general equation of dynamics in the form of the Lagrange equation by introducing generalized coordinates. Then, in 1834, Hamilton developed Analytical Mechanics. The Hamilton principle and Hamilton canonical equation are the core of Hamiltonian mechanics. The Hamilton principle is highly universal and can be used for approximate calculation [1,2]. The Hamilton principle is also extended to holonomic nonconservative systems [3] and high-order systems [4]. As for the Hamilton canonical equation, it is not only simpler in form than the Lagrange equation, but it is also more convenient for general discussion when solving many complex mechanical problems, such as celestial mechanics and vibration theory. What is more, Hamiltonian mechanics also contributes to the formation and development of generalized Hamiltonian mechanics [5] and Birkhoffian mechanics [6]. Thanks to Hamiltonian mechanics, the rapid development of nonlinear science in the last century has been possible. Hamiltonian mechanics is still a keyword today.
Fractional calculus has been widely considered. The latest developments in science, bioengineering and applied mathematics show that the results obtained through fractional calculus are more accurate [7,8]. In order to deal with dissipative forces in nonconservative systems, Riewe [9,10] studied the fractional calculus of variational problems and established fractional Lagrangian and Hamiltonian mechanics. After that, fractional Hamiltonian mechanics was established on the basis of different fractional derivatives. For example, Song [11] studied fractional singular systems and fractional constrained Hamilton equations using mixed derivatives. Baleanu [12] established fractional Hamilton formalism within Caputo’s derivatives. Rabei [13] achieved the passage from the Lagrangian, containing Riemann–Liouville fractional derivatives, to the Hamiltonian, and investigated the classical fields with fractional derivatives—he considered two discrete problems and one continuous to demonstrate the application of the formalism. Klimek [14] discussed the models described by fractional order derivatives of the Riemann–Liouville type in sequential form in Lagrangian and Hamiltonian formalism. Herzallah [15] presented fractional Euler–Lagrange equations and transversality conditions for fractional variational problems in the sense of Caputo and Riemann–Liouville fractional derivatives, and then he developed a fractional Hamiltonian formulation and some illustrative examples in detail. Muslih [16] presented a Hamiltonian formulation of systems with linear velocities within Riemann–Liouville fractional derivatives. Agrawal [17] introduced a three-parameter fractional derivative, developed integration by parts formulae, and provided the corresponding fractional Hamiltonian formulations. Nawafleh [18] investigated Caputo fractional derivatives for classical field systems using fractional Hamiltonian formalism and provided two continuous examples to demonstrate the application of the formalism. Notably, in 2010, Agrawal [19] introduced three general fractional operators, which we call generalized operators. Generalized operators contain many special fractional operators, such as Riemann–Liouville fractional operators, Caputo fractional operators, Riesz–Riemann–Liouville fractional operators, Riesz–Caputo fractional operators, etc. In this paper, we detail the beginning of our research, which is to establish Hamiltonian mechanics based on these generalized operators.
After the fractional differential equations are established, the next step is to solve them. An integral is a conserved quantity; therefore, scholars are committed to finding all conserved quantities of mechanics systems. The Noether symmetry method is one of the most useful methods for finding solutions to the differential equations of motion.
Noether symmetry and conserved quantity, which are useful for revealing the inherent physical properties of the dynamic systems, were put forward by German mathematician Emmy Noether [20]. Noether symmetry, from which the conserved quantity can be directly derived, refers to the invariance of the Hamilton action under infinitesimal transformations. A series of important achievements on Noether symmetry and conserved quantity for constrained mechanics systems has already been obtained, such as classical Noether theorems [21,22,23,24,25,26], fractional Noether theorems [27,28,29,30,31,32,33,34,35], Noether theorems on time scales [36,37,38], Noether theorems with time delay [39], etc.
For general dynamic problems, we should study the invariance property of mechanics systems, and the impact of this invariance on the behavior of the mechanics systems is also increasingly being valued. Zhao [24] pointed out that symmetry is a very important and universal property of mechanics systems. There is a close relationship between the change in symmetry under the action of small disturbances and their invariants and the integrability of mechanics systems, so it is necessary to study this carefully. The adiabatic invariant belongs to this problem. The classical adiabatic invariant refers to a physical quantity that changes more slowly than the change of the system’s changed parameter. Adiabatic refers to regardless the reasons of the cause of the parameter’s change in mechanics system. When discussing the adiabatic invariant, the problem of a slow-changing parameter is often discussed, which can be transformed into a small perturbation problem to be studied. The existence of invariants in a mechanics system often corresponds to its symmetry. Although the adiabatic invariant refers to a quantity that is approximately constant under certain conditions, there should be some symmetry corresponding to it, and the response of the symmetry may not be changed or may be perturbed. In this paper, perturbation to Noether symmetry and the corresponding adiabatic invariant of the Hamiltonian system are to be discussed under generalized operators.
The structure of this paper is as follows. Section 2 briefly lists the definitions and properties of the generalized operators. The fractional variational problems are studied in Section 3. Noether symmetry and conserved quantity, perturbation to Noether symmetry and adiabatic invariants are investigated in Section 4 and Section 5, respectively. Section 6 presents two examples to show the methods and results obtained in this paper. In Section 7, a conclusion is given.

2. Preliminaries

Generalized operators K , A , and B are introduced by Agrawal [19]. Here, we only list their definitions and integration by part formulae.
The operators K , A , and B are defined as:
K M α f ( t ) = m a t κ α ( t , τ ) f ( τ ) d τ + ω t b κ α ( τ , t ) f ( τ ) d τ ,   α > 0
A M α f ( t ) = D n Κ M n α f ( t ) ,   n 1 < α < n ,
B M α f ( t ) = Κ M n α D n f ( t ) ,   n 1 < α < n ,
where f ( t ) is continuous and integrable, a < t < b , M = < a , t , b , m , ω > is a parameter set, m and ω are two real numbers, n is an integer, and κ α ( t , τ ) is a kernel that probably depend on a parameter α .
Remark 1.
Let  κ α ( t , τ ) = ( t τ ) α 1 / Γ ( α ) . When the conditions are different, the results are different. For example, when M = M 1 = < a , t , b , 1 , 0 > , we can obtain:
A M α f ( t ) = D n K M n α f ( t ) = 1 Γ ( n α ) ( d d t ) n a t ( t τ ) n α 1 f ( τ ) d τ = D a R L t α f ( t ) ,
B M α f ( t ) = K M n α D n f ( t ) = 1 Γ ( n α ) a t ( t τ ) n α 1 ( d d τ ) n f ( τ ) d τ = D a C t α f ( t ) ,
i.e., the operator  A  reduces to the Riemann–Liouville fractional operator to the left, and the operator  B  reduces to the Caputo fractional operator to the left. When  M = M 3 =   < a , t , b , 1 / 2 , 1 / 2 > , we can obtain:
A M α f ( t ) = D n K M n α f ( t ) = 1 2 Γ ( n α ) ( d d t ) n b a | t τ | n α 1 f ( τ ) d τ = D a R b α f ( t ) ,
B M α f ( t ) = K M n α D n f ( t ) = 1 2 Γ ( n α ) a b | t τ | n α 1 ( d d τ ) n f ( τ ) d τ = D a R C b α f ( t ) ,
i.e., the operator  A  reduces to the Riesz–Riemann–Liouville fractional operator, and the operator  B  reduces to the Riesz–Caputo fractional operator.
The integrations by parts formulae of operators K , A and B are
a b g ( t ) K M α f ( t ) d t = a b f ( t ) K M * α g ( t ) d t ,
a b g ( t ) A M α f ( t ) d t = ( 1 ) n a b f ( t ) B M α g ( t ) d t + j = 0 n 1 ( D ) n 1 j g ( t ) A M α + j n f ( t ) | t = a t = b ,
a b g ( t ) B M α f ( t ) = ( 1 ) n a b f ( t ) A M α g ( t ) d t + j = 0 n 1 ( 1 ) j A M α + j n g ( t ) D n 1 j f ( t ) | t = a t = b ,
where M * = < a , t , b , ω , m > ,   n 1 < α < n , and n is an integer.
It is noted that in the following text we set n = 1 , so 0 < α < 1 . The first thing we intend to study is the variational problem.

3. Hamilton Equations within Generalized Operators

3.1. Hamilton Equation within Generalized Operator A

Let L A = L A ( t , q A , q ˙ A , A M α q A ) be the Lagrangian within generalized operator A , q A = ( q A 1 , q A 2 , , q A n ) , q ˙ A = ( q ˙ A 1 , q ˙ A 2 , , q ˙ A n ) and A M α q A = ( A M α q A 1 , A M α q A 2 , , A M α q A n ) , then the elements of the generalized moments p A = ( p A 1 , p A 2 , , p A n ) and p A α = ( p A 1 α , p A 2 α , , p A n α ) are defined as p A i = L A / q ˙ A i and p A i α = L A / A M α q A i , and the Hamiltonian H A = H A ( t , q A , p A , p A α ) can be expressed as H A = p A i q ˙ A i + p A i α A M α q A i L A , i = 1 , 2 , n .
Hamilton action within generalized operator A has the form
S A = a b [ p A i q ˙ A i + p A i α A M α q A i H A ( t , q A , p A , p A α ) ] d t .
Then,
δ S A = 0 ,
where δ refers to the isochronous variation, with the commutative conditions
δ A M α q A i = A M α δ q A i ,   i = 1 , 2 , , n ,
and the boundary conditions
q A ( a ) = q A a ,   q A ( b ) = q A b ,
where q A a = ( q A a 1 , q A a 2 , , q A a n ) , q A b = ( q A b 1 , q A b 2 , , q A b n ) , is called the Hamilton principle within generalized operator A .
Using Equations (9), (13) and (14), we derive from Equation (12) that
δ S A = a b [ δ p A i q ˙ A i + p A i δ q ˙ A i + δ p A i α A M α q A i + p A i α δ A M α q A i H A q A i δ q A i H A p A i δ p A i H A p A i α δ p A i α ] d t = a b [ ( B M * α p A i α + p ˙ A i + H A q A i m p A i α ( b ) κ 1 α ( b , t ) + ω p A i α ( a ) κ 1 α ( t , a ) ) δ q A i + ( q ˙ A i H A p A i ) δ p A i + ( A M α q A i H A p A i α ) δ p A i α ] d t = 0 .
From the Hamiltonian H A = p A i q ˙ A i + p A i α A M α q A i L A , the independence of δ q A i and the arbitrariness of the interval [ a , b ] , we obtain:
A M α q A i = H A p A i α ,   q ˙ A i = H A p A i , B M * α p A i α = p ˙ A i H A q A i + m p A i α ( b ) κ 1 α ( b , t ) ω p A i α ( a ) κ 1 α ( t , a ) .
Equation (16) is called the Hamilton equation within generalized operator A .
Remark 2.
Let  κ α ( t , τ ) = ( t τ ) α 1 / Γ ( α ) , when  M = M 1 ,  M = M 2  and  M = M 3 . From Equation (16), we can obtain the Hamilton equations within the left Riemann–Liouville fractional operator, the right Riemann–Liouville fractional operator, and the Riesz–Riemann–Liouville fractional operator, respectively. These results are consistent with the ones in Ref. [29].

3.2. Hamilton Equation within Generalized Operator B

Let L B = L B ( t , q B , q ˙ B , B M α q B ) be the Lagrangian within generalized operator B , q B = ( q B 1 , q B 2 , , q B n ) , q ˙ B = ( q ˙ B 1 , q ˙ B 2 , , q ˙ B n ) and B M α q B = ( B M α q B 1 , B M α q B 2 , , B M α q B n ) , then the elements of the generalized moments p B = ( p B 1 , p B 2 , , p B n ) and p B α = ( p B 1 α , p B 2 α , , p B n α ) are defined as p B i = L B / q ˙ B i and p B i α = L B / B M α q B i , and the Hamiltonian H B = H B ( t , q B , p B , p B α ) can be expressed as H B = p B i q ˙ B i + p B i α B M α q B i L B , i = 1 , 2 , n .
Hamilton action within generalized operator B can be expressed as
S B = a b [ p B i q ˙ B i + p B i α B M α q B i H B ( t , q B , p B , p B α ) ] d t .
Then,
δ S B = 0 ,
with the commutative conditions
δ B M α q B i = B M α δ q B i ,     i = 1 , 2 , , n ,
and the boundary conditions
q B ( a ) = q B a ,   q B ( b ) = q B b ,
where q B a = ( q B a 1 , q B a 2 , , q B a n ) , q B b = ( q B b 1 , q B b 2 , , q B b n ) , is called the Hamilton principle within generalized operator B .
Using Equations (10), (19) and (20), we derive from Equation (18) that
δ S B = a b [ δ p B i q ˙ B i + p B i δ q ˙ B i + δ p B i α B M α q B i + p B i α δ B M α q B i H B q B i δ q B i H B p B i δ p B i H B p B i α δ p B i α ] d t = a b [ ( A M α p B i α + p ˙ B i + H B q B i ) δ q B i + ( q ˙ B i H B p B i ) δ p B i + ( B M α q B i H B p B i α ) δ p B i α ] d t = 0 .
From the Hamiltonian H B = p B i q ˙ B i + p B i α B M α q B i L B , the independence of δ q B i and the arbitrariness of the interval [ a , b ] , we obtain:
B M α q B i = H B p B i α ,   q ˙ B i = H B p B i ,   A M α p B i α = p ˙ B i H B q B i .
Equation (22) is called the Hamilton equation within generalized operator B .
Remark 3.
Let  κ α ( t , τ ) = ( t τ ) α 1 / Γ ( α ) . When  M = M 1 ,  M = M 2  and  M = M 3 , from Equation (22), we can obtain the Hamilton equations in terms of the left Caputo fractional operator, the right Caputo fractional operator, and the Riesz–Caputo fractional operator, respectively. These results are consistent with the ones in Ref. [29].

4. Noether Theorems within Generalized Operators

We already know that Noether symmetry means the invariance of the Hamilton action under infinitesimal transformations, and the conserved quantity of the system can be directly derived from Noether symmetry. We begin with the definition of conserved quantity.
Definition 1.
A quantity  I  is called a conserved quantity if and only if the condition  d I / d t = 0  holds.

4.1. Noether Theorem within Generalized Operator A

Firstly, we give the infinitesimal transformations in terms of generalized operator A as
t ¯ = t + Δ t ,   q ¯ A i ( t ¯ ) = q A i ( t ) + Δ q A i ,   p ¯ A i ( t ¯ ) = p A i ( t ) + Δ p A i ,   p ¯ A i α ( t ¯ ) = p A i α ( t ) + Δ p A i α .
Expanding Equation (23), we have
t ¯ = t + θ A ξ A 0 0 ( t , q A , p A , p A α ) + ο ( θ A ) ,   q ¯ A i ( t ¯ ) = q A i ( t ) + θ A ξ A i 0 ( t , q A , p A , p A α ) + ο ( θ A ) , p ¯ A i ( t ¯ ) = p A i ( t ) + θ A η A i 0 ( t , q A , p A , p A α ) + ο ( θ A ) , p ¯ A i α ( t ¯ ) = p A i α ( t ) + θ A η A i α 0 ( t , q A , p A , p A α ) + ο ( θ A ) .
where θ A is an infinitesimal parameter, ξ A 0 0 , ξ A i 0 , η A i 0 and η A i α 0 are called infinitesimal generators within generalized operator A , and ο ( θ A ) means the higher-order infinity small of θ A .
Then, letting Δ S A be the linear part of S ¯ A S A and neglecting the higher-order infinity small of θ A , we obtain:
Δ S A = S ¯ A S A = a ¯ b ¯ [ p ¯ A i q ¯ ˙ A i + p ¯ A i α A M ¯ α q ¯ A i H A ( t , q ¯ A , p ¯ A , p ¯ A α ) d t ¯ a b [ p A i q ˙ A i + p A i α A M α q A i H A ( t , q A , p A , p A α ) ] d t = a b { ( p A i + Δ p A i ) ( q ˙ A i + Δ q ˙ A i ) + ( p A i α + Δ p A i α ) [ A M α q A i + A M α δ q A i + Δ t d d t A M α q A i + ω Δ b q A i ( b ) d d t κ 1 α ( b , t ) m Δ a q A i ( a ) d d t κ 1 α ( t , a ) ] H A ( t + Δ t , q A + Δ q A , p A + Δ p A , p A α + Δ p A α ) } ( 1 + d d t Δ t ) d t a b [ p A i q ˙ A i + p A i α A M α q A i H A ( t , q A , p A , p A α ) ] d t = a b { p A i q ˙ A i + p A i Δ q ˙ A i + Δ p A i q ˙ A i + p A i α A M α q A i + p A i α A M α δ q A i + p A i α Δ t d d t A M α q A i + Δ p A i α A M α q A i + p A i α [ ω Δ b q A i ( b ) d d t κ 1 α ( b , t ) m Δ a q A i ( a ) d d t κ 1 α ( t , a ) ] H A ( t , q A , p A , p A α ) H A t Δ t H A q A i Δ q A i H A p A i Δ p A i H A p A i α Δ p A i α + ( p A i q ˙ A i + p A i α A M α q A i H A ) d d t Δ t } d t a b [ p A i q ˙ A i + p A i α A M α q A i H A ( t , q A , p A , p A α ) ] d t = θ A a b { p A i ξ ˙ A i 0 + p A i α A M α ( ξ A i 0 q ˙ A i ξ A 0 0 ) + ( p A i α d d t A M α q A i H A t ) ξ A 0 0 + ( p A i α A M α q A i H A ) ξ ˙ A 0 0 H A q A i ξ A i 0 + ω q A i ( b ) p A i α ξ A 0 0 ( b , q A ( b ) , p A ( b ) , p A α ( b ) ) × d d t κ 1 α ( b , t ) m q A i ( a ) p A i α ξ A 0 0 ( a , q A ( a ) , p A ( a ) , p A α ( a ) ) d d t κ 1 α ( t , a ) } d t .
where
A M ¯ α q ¯ A i = A M α q A i + A M α δ q A i + Δ t d d t A M α q A i + ω Δ b q A i ( b ) d d t κ 1 α ( b , t ) m Δ a × q A i ( a ) d d t κ 1 α ( t , a ) ,   Δ q ˙ A i = θ A ( ξ ˙ A i 0 q ˙ A i ξ ˙ A 0 0 ) ,   M ¯ = < a ¯ , t ¯ , b ¯ , m , ω > .
It follows from Noether symmetry ( Δ S A = 0 ) that
p A i ξ ˙ A i 0 + p A i α A M α ( ξ A i 0 q ˙ A i ξ A 0 0 ) + ( p A i α d d t A M α q A i H A t ) ξ A 0 0 H A q A i ξ A i 0 + ω p A i α × q A i ( b ) ξ A 0 0 ( b , q A ( b ) , p A ( b ) , p A α ( b ) ) d d t κ 1 α ( b , t ) + ( p A i α A M α q A i H A ) ξ ˙ A 0 0 m p A i α q A i ( a ) ξ A 0 0 ( a , q A ( a ) , p A ( a ) , p A α ( a ) ) d d t κ 1 α ( t , a ) = 0 ,     i = 1 , 2 , , n .
Equation (27) is called the Noether identity within generalized operator A .
Finally, the conserved quantity within generalized operator A deduced by the Noether symmetry is presented.
Theorem 1.
For the Hamiltonian system within generalized operator  A  (Equation (16)), if the infinitesimal generators  ξ A 0 0 ,  ξ A i 0 ,  η A i 0  and  η A i α 0  satisfy the Noether identity (Equation (27)), then there exists a conserved quantity:
I A 0 = ( p A i α A M α q A i H A ) ξ A 0 0 + a t { p A i α A M α ( ξ A i 0 q ˙ A i ξ A 0 0 ) + ( ξ A i 0 q ˙ A i ξ A 0 0 ) × [ B M * α p A i α m p A i ( b ) κ 1 α ( b , τ ) + ω p A i ( a ) κ 1 α ( τ , a ) ] } d τ + p A i ξ A i 0 + ω q A i ( b ) ξ A 0 0 ( b , q A ( b ) , p A ( b ) , p A α ( b ) ) a t p A i α ( τ ) d d τ κ 1 α ( b , τ ) d τ m q A i ( a ) ξ A 0 0 ( a , q A ( a ) , p A ( a ) , p A α ( a ) ) a t p A i α ( τ ) d d τ κ 1 α ( τ , a ) d τ = const .
Proof of Theorem 1.
From Equations (16) and (27), we have:
d d t I A 0 = ( p ˙ A i α A M α q A i + p A i α d d t A M α q A i H A t H A q A i q ˙ A i H A p A i p ˙ A i H A p A i α p ˙ A i α ) ξ A 0 0 + ( p A i α A M α q A i H A ) ξ ˙ A 0 0 + p A i α A M α ( ξ A i 0 q ˙ A i ξ A 0 0 ) + ( ξ A i 0 q ˙ A i ξ A 0 0 ) [ B M * α p A i α m p A i α ( b ) κ 1 α ( b , τ ) + ω p A i α ( a ) κ 1 α ( τ , a ) ] + p ˙ A i ξ A i 0 + p A i ξ ˙ A i 0 + ω p A i α q A i ( b ) ξ A 0 0 ( b , q A ( b ) , p A ( b ) , p A α ( b ) ) d d t κ 1 α ( b , t ) m p A i α q A i ( a ) ξ A 0 0 ( a , q A ( a ) , p A ( a ) , p A α ( a ) ) d d t κ 1 α ( t , a )   = H A q A i ξ A i + p ˙ A i ξ A i 0 + ( p ˙ A i α A M α q A i H A q A i q ˙ A i H A p A i p ˙ A i H A p A i α p ˙ A i α ) ξ A 0 0 + ( ξ A i 0 q ˙ A i ξ A 0 0 ) [ B M * α p A i α m p A i α ( b ) κ 1 α ( b , τ ) + ω p A i α ( a ) κ 1 α ( τ , a ) ] = ( A M α q A i H A p A i α ) p ˙ A i α ξ A 0 0 + ( ξ A i 0 q ˙ A i ξ A 0 0 ) [ B M * α p A i α + p ˙ A i + H A q A i m p A i α ( b ) κ 1 α ( b , t ) + ω p A i α ( a ) κ 1 α ( t , a ) ] = 0 .
The proof is completed. □
If we let Δ S A = a b ( d / d t ) ( Δ G A 0 ) d t , where Δ G A 0 = θ A G A 0 ( t , q A , p A , p A α ) , then from Equation (25), we have
p A i ξ ˙ A i 0 + p A i α A M α ( ξ A i 0 q ˙ A i ξ A 0 0 ) + ( p A i α d d t A M α q A i H A t ) ξ A 0 0 H A q A ξ A i 0 + ω p A i α q A i ( b ) × ξ A 0 0 ( b , q A ( b ) , p A ( b ) , p A α ( b ) ) d d t κ 1 α ( b , t ) + ( p A i α A M α q A i H A ) ξ ˙ A 0 0 + G ˙ A 0 m p A i α q A i ( a ) ξ A 0 0 ( a , q A ( a ) , p A ( a ) , p A α ( a ) ) d d t κ 1 α ( t , a ) = 0 ,     i = 1 , 2 , , n .
Equation (30) is called the Noether quasi-identity within generalized operator A . In this case, we have the following theorem.
Theorem 2.
For the Hamiltonian system within the generalized operator  A  (Equation (16)), if there exists a function  G A 0  such that the infinitesimal generators  ξ A 0 0 ,  ξ A i 0 ,  η A i 0  and  η A i α 0  satisfy the Noether quasi-identity (Equation (30)), then there exists a conserved quantity
I A G 0 = ( p A i α A M α q A i H A ) ξ A 0 0 + p A i ξ A i 0 + a t { p A i α A M α ( ξ A i 0 q ˙ A i ξ A 0 0 ) + ( ξ A i 0 q ˙ A i ξ A 0 0 ) × [ B M * α p A i α m p A i ( b ) κ 1 α ( b , τ ) + ω p A i ( a ) κ 1 α ( τ , a ) ] } d τ + ω q A i ( b ) × ξ A 0 0 ( b , q A ( b ) , p A ( b ) , p A α ( b ) ) a t p A i α ( τ ) d d τ κ 1 α ( b , τ ) d τ m q A i ( a ) × ξ A 0 0 ( a , q A ( a ) , p A ( a ) , p A α ( a ) ) a t p A i α ( τ ) d d τ κ 1 α ( τ , a ) d τ + G A 0 = const .
Proof of Theorem 2.
From Equations (16) and (30), we have d I A G 0 / d t = 0 .
The proof is completed. □
Remark 4.
Let  κ α ( t , τ ) = ( t τ ) α 1 / Γ ( α ) . When  M = M 1 ,  M = M 2  and  M = M 3 , from Equations (27) and (30) and Theorems 1 and 2, we can obtain Noether identities, Noether quasi-identities, and Noether theorems in terms of the left Riemann–Liouville fractional operator, the right Riemann–Liouville fractional operator, and the Riesz–Riemann–Liouville fractional operator, respectively. These results are consistent with the ones in Ref. [29].

4.2. Noether Theorem within Generalized Operator B

The infinitesimal transformations in terms of generalized operator B are
t ¯ = t + Δ t ,   q ¯ B i ( t ¯ ) = q B i ( t ) + Δ q B i ,   p ¯ B i ( t ¯ ) = p B i ( t ) + Δ p B i ,   p ¯ B i α ( t ¯ ) = p B i α ( t ) + Δ p B i α .
Expanding Equation (32), we have
t ¯ = t + θ B ξ B 0 0 ( t , q B , p B , p B α ) + ο ( θ B ) ,   q ¯ B i ( t ¯ ) = q B i ( t ) + θ B ξ B i 0 ( t , q B , p B , p B α ) + ο ( θ B ) , p ¯ B i ( t ¯ ) = p B i ( t ) + θ B η B i 0 ( t , q B , p B , p B α ) + ο ( θ B ) , p ¯ B i α ( t ¯ ) = p B i α ( t ) + θ B η B i α 0 ( t , q B , p B , p B α ) + ο ( θ B ) ,
where θ B is an infinitesimal parameter, ξ B 0 0 , ξ B i 0 , η B i 0 and η B i α 0 are called infinitesimal generators within generalized operator B , and ο ( θ B ) means the higher-order infinity small of θ B .
Similarly, letting Δ S B be the linear part of S ¯ B S B and neglecting the higher-order infinity small of θ B , we obtain
Δ S B = S B ¯ S B = a ¯ b ¯ [ p ¯ B i q ¯ ˙ B i + p ¯ B i α B M ¯ α q ¯ B i H B ( t , q ¯ B , p ¯ B , p ¯ B α ) ] d t ¯ a b [ p B i q ˙ B i + p B i α B M α q B i H B ( t , q B , p B , p B α ) ] d t = a b { ( p B i + Δ p B i ) ( q ˙ B i + Δ q ˙ B i ) + ( p B i α + Δ p B i α ) [ B M α q B i + B M α δ q B i + Δ t d d t B M α q B i + ω Δ b q ˙ B i ( b ) κ 1 α ( b , t ) m Δ a q ˙ B i ( a ) κ 1 α ( t , a ) ] H B ( t + Δ t , q B + Δ q B , p B + Δ p B , p B α + Δ p B α ) } ( 1 + d d t Δ t ) d t a b [ p B i q ˙ B i + p B i α B M α q B i H B ( t , q B , p B , p B α ) ] d t = a b { p B i q ˙ B i + p B i Δ q ˙ B i + Δ p B i q ˙ B i + p B i α B M α q B i + p B i α B M α δ q B i + p B i α Δ t d d t B M α q B i + Δ p B i α B M α q B i + p B i α [ ω Δ b q ˙ B i ( b ) κ 1 α ( b , t ) m Δ a q ˙ B i ( a ) κ 1 α ( t , a ) ] H B ( t , q B , p B , p B α ) H B t Δ t H B q B i Δ q B i H B p B i Δ p B i H B p B i α Δ p B i α + ( p B i q ˙ B i + p B i α B M α q B i H B ) d d t Δ t } d t a b [ p B i q ˙ B i + p B i α B M α q B i H B ( t , q B , p B , p B α ) ] d t = θ B a b [ p B i ξ ˙ B i 0 + p B i α B M α ( ξ B i 0 q ˙ B i ξ B 0 0 ) + ( p B i α d d t B M α q B i H B t ) ξ B 0 0 + ( p B i α B M α q B i H B i ) ξ ˙ B 0 0 H B q B i ξ B i 0 + ω q ˙ B i ( b ) p B i α ξ B 0 0 ( b , q B ( b ) , p B ( b ) , p B α ( b ) ) κ 1 α ( b , t ) m q ˙ B i ( a ) p B i α ξ B 0 0 ( a , q B ( a ) , p B ( a ) , p B α ( a ) ) κ 1 α ( t , a ) ] d t ,
where
B M ¯ α q ¯ B i = B M α q B i + B M α δ q B i + Δ t d d t B M α q B i + ω Δ b q ˙ B i ( b ) κ 1 α ( b , t ) m Δ a × q ˙ B i ( a ) κ 1 α ( t , a ) ,   Δ q ˙ B i = θ B ( ξ ˙ B i 0 q ˙ B i ξ ˙ B 0 0 ) ,   M ¯ = < a ¯ , t ¯ , b ¯ , m , ω > .
Letting Δ S B = 0 , we have
p B i ξ ˙ B i 0 + p B i α B M α ( ξ B i 0 q ˙ B i ξ B 0 0 ) + ( p B i α d d t B M α q B i H B t ) ξ B 0 0 H B q B i ξ B i 0 + ( p B i α B M α q B i H B ) ξ ˙ B 0 0 + ω p B i α q ˙ B i ( b ) ξ B 0 0 ( b , q B ( b ) , p B ( b ) , p B α ( b ) ) κ 1 α ( b , t ) m p B i α q ˙ B i ( a ) ξ B 0 0 ( a , q B ( a ) , p B ( a ) , p B α ( a ) ) κ 1 α ( t , a ) = 0 ,     i = 1 , 2 , , n .
Equation (36) is called the Noether identity within generalized operator B .
If we let Δ S B = a b ( d / d t ) ( Δ G B 0 ) d t , Δ G B 0 = θ B G B 0 ( t , q B , p B , p B α ) , then from Equation (34), we have
p B i ξ ˙ B i 0 + p B i α B M α ( ξ B i 0 q ˙ B i ξ B 0 0 ) + ( p B i α d d t B M α q B i H B t ) ξ B 0 0 H B q B i ξ B i 0 + ( p B i α B M α q B i H B ) ξ ˙ B 0 0 + ω p B i α q ˙ B i ( b ) ξ B 0 0 ( b , q B ( b ) , p B ( b ) , p B α ( b ) ) κ 1 α ( b , t ) m p B i α q ˙ B i ( a ) ξ B 0 0 ( a , q B ( a ) , p B ( a ) , p B α ( a ) ) κ 1 α ( t , a ) + G ˙ B 0 = 0 ,     i = 1 , 2 , , n .
Equation (37) is called the Noether quasi-identity within generalized operator B . Therefore, we have the following theorem.
Theorem 3.
For the Hamiltonian system within generalized operator  B  (Equation (22)), if the infinitesimal generators  ξ B 0 0 ,  ξ B i 0 ,  η B i 0  and  η B i α 0  satisfy the Noether identity (Equation (36)), then there exists a conserved quantity
I B 0 = ( p B i α B M α q B i H B ) ξ B 0 0 + a t [ p B i α B M α ( ξ B i 0 q ˙ B i ξ B 0 0 ) + ( ξ B i 0 q ˙ B i ξ B 0 0 ) A M * α p B i α ] d τ + p B i ξ B i 0 + ω q ˙ B i ( b ) ξ B 0 0 ( b , q B ( b ) , p B ( b ) , p B α ( b ) ) a t p B i α ( τ ) κ 1 α ( b , τ ) d τ m q ˙ B i ( a ) ξ B 0 0 ( a , q B ( a ) , p B ( a ) , p B α ( a ) ) a t p B i α ( τ ) κ 1 α ( τ , a ) d τ = const .
Proof of Theorem 3.
From Equations (22) and (36), we obtain:
d d t I B 0 = ( p ˙ B i α B M α q B i + p B i α d d t B M α q B i H B t H B q B i q ˙ B i H B p B i p ˙ B i H B p B i α p ˙ B i α ) ξ B 0 0 + ( p B i α B M α q B i H B ) ξ ˙ B 0 0 + p B i α B M α ( ξ B i 0 q ˙ B i ξ B 0 0 ) + ( ξ B i 0 q ˙ B i ξ B 0 0 ) A M * α p B i α + p ˙ B i ξ B i + p B i ξ ˙ B i 0 + ω p B i α q ˙ B i ( b ) ξ B 0 0 ( b , q B ( b ) , p B ( b ) , p B α ( b ) ) κ 1 α ( b , t ) m p B i α q ˙ B i ( a ) ξ B 0 0 ( a , q B ( a ) , p B ( a ) , p B α ( a ) ) κ 1 α ( t , a ) = H B q B i ξ B i 0 + p ˙ B i ξ B i 0 + ( p ˙ B i α B M α q B i H B q B i q ˙ B i H B p B i p ˙ B i H B p B i α p ˙ B i α ) ξ B 0 0 + ( ξ B i 0 q ˙ B i ξ B 0 0 ) A M * α p A i α = ( B M α q B i H B p B i α ) p ˙ B i α ξ B 0 0 + ( ξ B i 0 q ˙ B i ξ B 0 0 ) ( A M * α p B i α + p ˙ B i + H B q B i ) = 0 .
The proof is completed. □
Theorem 4.
For the Hamiltonian system within generalized operator  B  (Equation (22)), if there exists a function  G B 0  such that the infinitesimal generators  ξ B 0 ,  ξ B i ,  η B i  and  η B i α  satisfy the Noether quasi-identity (Equation (37)), then there exists a conserved quantity
I B G 0 = ( p B i α B M α q B i H B ) ξ B 0 0 + a t [ p B i α B M α ( ξ B i 0 q ˙ B i ξ B 0 0 ) + ( ξ B i 0 q ˙ B i ξ B 0 0 ) A M * α p B i α ] d τ + p B i ξ B i 0 + ω q ˙ B i ( b ) ξ B 0 0 ( b , q B ( b ) , p B ( b ) , p B α ( b ) ) a t p B i α ( τ ) κ 1 α ( b , τ ) d τ m q ˙ B i ( a ) ξ B 0 0 ( a , q B ( a ) , p B ( a ) , p B α ( a ) ) a t p B i α ( τ ) κ 1 α ( τ , a ) d τ + G B 0 = const .
Proof of Theorem 4.
From Equations (22) and (37), we have d I B G 0 / d t = 0 .
The proof is completed. □
Remark 5.
Let  κ α ( t , τ ) = ( t τ ) α 1 / Γ ( α ) . When    M = M 1 ,    M = M 2  and  M = M 3  from Equation (36) and Equation (37) and Theorems 3 and 4, we can obtain Noether identities, Noether quasi-identities, and Noether theorems in terms of the left Caputo fractional operator, the right Caputo fractional operator and the Riesz–Caputo fractional operator, respectively. These results are consistent with the ones in Ref. [29].

5. Adiabatic Invariants within Generalized Operators

First, we give the definition of an adiabatic invariant.
Definition 2.
A quantity  I z  is called an adiabatic invariant if  I z  contains a parameter  ε , whose highest power is  z , and also satisfies that  d I z / d t  is in proportion to  ε z + 1 .
When the systems (Equations (16) and (22)) are disturbed by small forces, the conserved quantities may also change.
Supposing that the Hamiltonian system (Equation (16)) is disturbed as
B M * α p A i α = p ˙ A i H A q A i + m p A i α ( b ) κ 1 α ( b , t ) ω p A i α ( a ) κ 1 α ( t , a ) ε A W A i ( t , q A , p A , p A α ) , A M α q A i = H A p A i α ,   q ˙ A i = H A p A i .
In this case, if the function G A and the infinitesimal generators ξ A 0 , ξ A i , η A i and η A i α of the disturbed system (Equation (41)) have the forms
G A = G A 0 + ε A G A 1 + ε A 2 G A 2 + = ε A s G A s , ξ A 0 = ξ A 0 0 + ε A ξ A 0 1 + ε A 2 ξ A 0 2 + = ε A s ξ A 0 s , η A i = η A i 0 + ε A η A i 1 + ε A 2 η A i 2 + = ε A s η A i s , η A i = η A i α 0 + ε A η A i α 1 + ε A 2 η A i α 2 + = ε A s η A i α s ,   i = 1 , 2 , , n ,   s = 0 , 1 , 2 , ,
then we have:
Theorem 5.
For the disturbed Hamiltonian system (Equation (41)), if there exists a function  G A s  such that the infinitesimal generators  ξ A 0 s ,  ξ A i s ,  η A i s  and  η A i α s  satisfy
p A i ξ ˙ A i s + p A i α A M α ( ξ A i s q ˙ A i ξ A 0 s ) + ( p A i α d d t A M α q A i H A t ) ξ A 0 s H A q A i ξ A i s + ( p A i α A M α q A i H A ) ξ ˙ A 0 s + ω p A i α q A i ( b ) ξ A 0 s ( b , q A ( b ) , p A ( b ) , p A α ( b ) ) d d t κ 1 α ( b , t ) + G ˙ A s m p A i α q A i ( a ) ξ A 0 s ( a , q A ( a ) , p A ( a ) , p A α ( a ) ) d d t κ 1 α ( t , a ) W A i ( ξ A i s 1 q ˙ A i ξ A 0 s 1 ) = 0 ,
where  ξ A i s 1 = ξ A 0 s 1 = 0  when  s = 0 , then there exists an adiabatic invariant
I A G z = Σ s = 0 z ε A s { ( p A i α A M α q A i H A ) ξ A 0 s + a t { p A i α A M α ( ξ A i s q ˙ A i ξ A 0 s ) + ( ξ A i s q ˙ A i ξ A 0 s ) × [ B M * α p A i α m p A i ( b ) κ 1 α ( b , τ ) + ω p A i ( a ) κ 1 α ( τ , a ) ] } d τ + p A i ξ A i s + ω q A i ( b ) ξ A 0 s ( b , q A ( b ) , p A ( b ) , p A α ( b ) ) a t p A i α ( τ ) d d τ κ 1 α ( b , τ ) d τ   m q A i ( a ) ξ A 0 s ( a , q A ( a ) , p A ( a ) , p A α ( a ) ) a t p A i α ( τ ) d d τ κ 1 α ( τ , a ) d τ + G A s } .
Proof of Theorem 5.
From Equations (41) and (43), we have:
d d t I A G z = Σ s = 0 z ε A s { ( p A i α A M α q A i H A ) ξ ˙ A 0 s + ( p ˙ A i α A M α q A i + p A i α d d t A M α q A i H A t H A q A i q ˙ A i H A p A i p ˙ A i H A p A i α p ˙ A i α ) ξ A 0 s + p A i α A M α ( ξ A i s q ˙ A i ξ A 0 s ) + ( ξ A i s q ˙ A i ξ A 0 s ) [ B M * α p A i α m p A i ( b ) κ 1 α ( b , τ ) + ω p A i ( a ) κ 1 α ( τ , a ) ] + p ˙ A i ξ A i s + p A i ξ ˙ A i s + ω p A i α q A i ( b ) ξ A 0 s ( b , q A ( b ) , p A ( b ) , p A α ( b ) ) d d t κ 1 α ( b , t ) m p A i α q A i ( a ) ξ A 0 s ( a , q A ( a ) , p A ( a ) , p A α ( a ) ) d d t κ 1 α ( t , a ) + G ˙ A s = Σ s = 0 z ε A s { H A q A ξ A i s + W A i ( ξ A i s 1 q ˙ A i ξ A 0 s 1 ) ( H A q A i q ˙ A i + H A p A i p ˙ A i ) ξ A 0 s + p ˙ A i ξ A i s + ( ξ A i s q ˙ A i ξ A 0 s ) [ B M * α p A i α m p A i ( b ) κ 1 α ( b , τ ) + ω p A i ( a ) κ 1 α ( τ , a ) ] } = Σ s = 0 z ε A s [ ε A W A i ( ξ A i s q ˙ A i ξ A 0 s ) + W A i ( ξ A i s 1 q ˙ A i ξ A 0 s 1 ) ] = ε A z + 1 W A i ( ξ A i z q ˙ A i ξ A 0 z ) .
This proof is completed. □
We assume that the Hamiltonian system (Equation (22)) is disturbed as
A M α p B i α = p ˙ B i H B q B i ε B W B i ( t , q B , p B , p B α ) ,   B M α q B i = H B p B i α ,   q ˙ B i = H B p B i .
In this case, if the function G B and the infinitesimal generators ξ B 0 , ξ B i , η B i and η B i α of the disturbed system (Equation (46)) have the forms
G B = G B 0 + ε B G B 1 + ε B 2 G B 2 + = ε B s G B s ,   ξ B 0 = ξ B 0 0 + ε B ξ B 0 1 + ε B 2 ξ B 0 2 + = ε B s ξ B 0 s , η B i = η B i 0 + ε B η B i 1 + ε B 2 η B i 2 + = ε B s η B i s ,   η B i = η B i α 0 + ε A η B i α 1 + ε A 2 η B i α 2 + = ε B s η B i α s , i = 1 , 2 , , n ,   s = 0 , 1 , 2 , ,
then we have:
Theorem 6.
For the disturbed Hamiltonian system (Equation(46)), if there exists a function  G B s  such that the infinitesimal generators  ξ B 0 s ,  ξ B i s ,  η B i s  and  η B i α s  satisfy
p B i ξ ˙ B i s + p B i α B M α ( ξ B i s q ˙ B i ξ B 0 s ) + ( p B i α d d t B M α q B i H B t ) ξ B 0 s H B q B i ξ B i s + ( p B i α B M α q B i H B ) ξ ˙ B 0 s + ω p B i α q ˙ B i ( b ) ξ B 0 s ( b , q B ( b ) , p B ( b ) , p B α ( b ) ) κ 1 α ( b , t ) m p B i α q ˙ B i ( a ) ξ B 0 s ( a , q B ( a ) , p B ( a ) , p B α ( a ) ) κ 1 α ( t , a ) W B i ( ξ B i s 1 q ˙ B i ξ B 0 s 1 ) + G ˙ B s = 0 ,
where  ξ B i s 1 = ξ B 0 s 1 = 0  when  s = 0 , then there exists an adiabatic invariant
I B G z = Σ s = 0 z ε B s { ( p B i α B M α q B i H B ) ξ B 0 s + a t [ p B i α B M α ( ξ B i s q ˙ B i ξ B 0 s ) + ( ξ B i s q ˙ B i ξ B 0 s ) × A M * α p B i α ] d τ + p B i ξ B i s + ω q ˙ B i ( b ) ξ B 0 s ( b , q B ( b ) , p B ( b ) , p B α ( b ) ) × a t p B i α ( τ ) κ 1 α ( b , τ ) d τ m q ˙ B i ( a ) ξ B 0 s ( a , q B ( a ) , p B ( a ) , p B α ( a ) ) × a t p B i α ( τ ) κ 1 α ( τ , a ) d τ + G B s } .
Proof of Theorem 6.
From Equations (46) and (48), we have:
d d t I B G z = Σ s = 0 z ε B s { ( p B i α B M α q B i H B ) ξ ˙ B 0 s + ( p ˙ B i α B M α q B i + p B i α d d t B M α q B i H B t H B q B i q ˙ B i H B p B i p ˙ B i H B p B i α p ˙ B i α ) ξ B 0 s + p B i α B M α ( ξ B i s q ˙ B i ξ B 0 s ) + ( ξ B i s q ˙ B i ξ B 0 s ) A M * α p B i α + p ˙ B i ξ B i s + p B i ξ ˙ B i s + ω p B i α q ˙ B i ( b ) ξ B 0 s ( b , q B ( b ) , p B ( b ) , p B α ( b ) ) κ 1 α ( b , t ) m p B i α q ˙ B i ( a ) ξ B 0 s ( a , q B ( a ) , p B ( a ) , p B α ( a ) ) κ 1 α ( t , a ) + G ˙ A s = Σ s = 0 z ε B s [ H B q B ξ B i s + W B i ( ξ B i s 1 q ˙ B i ξ B 0 s 1 ) ( H B q B i q ˙ B i + H B p B i p ˙ B i ) ξ B 0 s + p ˙ B i ξ B i s + ( ξ B i s q ˙ B i ξ B 0 s ) A M * α p B i α ] = Σ s = 0 z ε B s [ ε B W B i ( ξ B i s q ˙ B i ξ B 0 s ) + W B i ( ξ B i s 1 q ˙ B i ξ B 0 s 1 ) ] = ε B z + 1 W B i ( ξ B i z q ˙ B i ξ B 0 z ) .
This proof is completed. □
Remark 6.
Let  κ α ( t , τ ) = ( t τ ) α 1 / Γ ( α ) . When  M = M 1 ,  M = M 2  and  M = M 3 , we can obtain the adiabatic invariants in terms of the left Riemann–Liouville fractional operator, the right Riemann–Liouville fractional operator, the Riesz–Riemann–Liouville fractional operator, the left Caputo fractional operator, the right Caputo fractional operator, and the Riesz–Caputo fractional operator from Theorem 5 and Theorem 6, respectively. These results are consistent with the ones obtained in Ref. [29].
Remark 7.
If we let    α 1 , all the six cases in Remark 14 are simplified to the classical adiabatic invariant, which can also be found in Ref. [29].
Remark 8.
When    z = 0 , the conserved quantities of Theorems 2 and 4 can be obtained from the adiabatic invariants of Theorem 5 and Theorem 6, respectively.

6. Examples

In this section, two examples are given to illustrate the results and methods.
Example 1.
The Hamiltonian system within the generalized operator A.
For the Lagrangian,
L A = 1 2 m [ ( A M α q A 1 ) 2 + ( A M α q A 2 ) 2 + q ˙ A 1 2 + q ˙ A 2 2 ] ,
try to study its conserved quantity and adiabatic invariant.
From Equation (51), we have
p A 1 α = L A A M α q A 1 = m A M α q A 1 ,   p A 2 α = L A A M α q A 2 = m A M α q A 2 ,   p A 1 = L A q ˙ A 1 = m q ˙ A 1 , p A 2 = L A q ˙ A 2 = m q ˙ A 2 ,   H A = 1 2 m [ ( p A 1 α ) 2 + ( p A 2 α ) 2 + p A 1 2 + p A 2 2 ] .
Then, Equation (16) gives the Hamilton equation
A M α q A 1 = 1 m p A 1 α ,   A M α q A 2 = 1 m p A 2 α ,   q ˙ A 1 = 1 m p A 1 ,   q ˙ A 2 = 1 m p A 2 , B M * α p A 1 α = p ˙ A 1 + m p A 1 α ( b ) κ 1 α ( b , t ) ω p A 1 α ( a ) κ 1 α ( t , a ) , B M * α p A 2 α = p ˙ A 2 + m p A 2 α ( b ) κ 1 α ( b , t ) ω p A 2 α ( a ) κ 1 α ( t , a ) .
Under the condition ( d / d t ) κ α ( t , τ ) = ( d / d τ ) κ α ( t , τ ) , we can verify that
ξ A 0 0 = 1 ,   ξ A 1 0 = ξ A 2 0 = 0 ,   G A 0 = 0
satisfy the Noether quasi-identity (Equation (30)). Therefore, from Theorem 2, we have
I A G 0 = p A 1 α A M α q A 1 + p A 2 α A M α q A 2 H A a t { p A 1 α d d τ A M α q A 1 + q ˙ A 1 [ B M * α p A 1 α m p A 1 α ( b ) κ 1 α ( b , τ ) + ω p A 1 α ( a ) κ 1 α ( τ , a ) ] + p A 2 α d d τ A M α q A 2 + q ˙ A 2 [ B M * α p A 2 α m p A 2 α ( b ) κ 1 α ( b , τ ) + ω p A 2 α ( a ) κ 1 α ( τ , a ) ] } d τ = 1 2 m [ ( p A 1 α ) 2 + ( p A 2 α ) 2 p A 1 2 p A 2 2 ] a t { p A 1 α d d τ A M α q A 1 + q ˙ A 1 [ B M α p A 1 α m p A 1 α ( b ) κ 1 α ( b , τ ) + ω p A 1 α ( a ) κ 1 α ( τ , a ) ] + p A 2 α d d τ A M α q A 2 + q ˙ A 2 [ B M α p A 2 α m p A 2 α ( b ) κ 1 α ( b , τ ) + ω p A 2 α ( a ) κ 1 α ( τ , a ) ] } d τ = const .
When the system is disturbed by ε A W A 1 ( t , q A , p A , p A α ) = ε A q A 2 and ε A W A 2 ( t , q A , p A , p A α ) = ε A q A 1 , then we can find that
ξ A 0 1 = 1 ,   ξ A 1 1 = ξ A 2 1 = 0 ,   G A 1 = q A 1 q A 2
is a solution to Equation (43). Therefore, from Theorem 5, we obtain
I A G 1 = I A G 0 + ε A ( I A G 0 q A 1 q A 2 ) .
Specifically, let κ α ( t , τ ) = ( t τ ) α 1 / Γ ( α ) , M = M 1 (or M = M 2 or M = M 3 ) and   α 1 , we have
I A G 0 C = H A = const ,   I A G 1 C = H A ε A ( H A + q A 1 q A 2 ) .
Example 2.
The Hamiltonian system within the generalized operator B.
For the Lagrangian,
L B = 1 2 [ ( B M α q B ) 2 + q ˙ B 2 ] q B ,
try to find its conserved quantity and adiabatic invariant.
From Equation (59), we have
p B α = L B B M α q B = B M α q B ,   p B = L B q ˙ B = q ˙ B , H B = 1 2 [ ( p B α ) 2 + p B 2 ] + q B .
Then, Equation (22) gives the Hamilton equation
B M α q B = p B α ,   q ˙ B = p B ,   A M * α p B α = p ˙ B 1 .
Under the condition ( d / d t ) κ α ( t , τ ) = ( d / d τ ) κ α ( t , τ ) , we can verify that
ξ B 0 0 = 1 ,   ξ B 1 0 = 0 ,   G B 0 = 0
satisfy the Noether quasi-identity (Equation (37)). Therefore, from Theorem 4, we have
I B G 0 = p B α B M α q B H B a t ( q ˙ B A M * α p B α + p B α d d τ B M α q B ) d τ = 1 2 [ ( p B α ) 2 p B 2 2 q B ] a t ( q ˙ B A M * α p B α + p B α d d τ B M α q B ) d τ = const .
When the system is disturbed by ε B W B 1 ( t , q B , p B , p B α ) = ε B ( 2 q B 1 + 1 ) , then we can find that
ξ B 0 1 = 1 ,   ξ B 1 1 = 0 ,   G B 1 = q B 1 2 q B 1
is a solution to Equation (48). Therefore, from Theorem 6, we have
I B G 1 = I B G 0 + ε B ( I B G 0 q B 1 2 q B 1 ) .
Specifically, let κ α ( t , τ ) = ( t τ ) α 1 / Γ ( α ) , M = M 1 (or M = M 2 or M = M 3 ) and   α 1 , we have
I B G 0 C = H B = const ,   I B G 1 C = H B ε A ( H B + q B 1 2 + q B 1 ) .
Remark 9.
We only provide two illustrative examples to explain the obtained methods and results. In fact, the symmetry of the Hamiltonian system can be applied to many problems, such as the Lotka biochemical oscillator model, the Toda lattice with three particles, the Emden equation, etc. [22,23].

7. Conclusions

On the basis of the generalized operators, fractional variational problems are studied, Hamilton equations are established, and several special cases of the Hamilton equations are presented. Some results are consistent with the existing ones, while some are new. In order to reduce the degrees of the freedom of the differential equations and to better analyze the dynamic behaviors of the system, Noether symmetry and conserved quantities as well as perturbation to Noether symmetry and the corresponding adiabatic invariants are investigated. Hamilton equations (Equations (16) and (22)), Noether theorems (Theorems 1–4) and adiabatic invariants (Theorems 5 and 6) are all new work.
However, only the Noether symmetry method is studied here. In fact, fractional symmetry analysis and conservation laws can be adopted for many specific equations [40,41,42,43]. Particularly, for constrained mechanics systems, except for the Noether symmetry method, the Lie symmetry method and the Mei symmetry method are also two useful methods for solving differential equations of motion. The Lie symmetry is a kind of invariance of the differential equations under the infinitesimal transformations of time and coordinates. The Mei symmetry is a kind of invariance under which the transformed dynamical functions still satisfy the original differential equations of motion. The relationships between the three symmetry methods can be read in Ref. [21]. Therefore, the Lie symmetry method and the Mei symmetry method are to be studied in the near future.

Author Contributions

C.W. wrote the first draft of the manuscript. C.-J.S. reviewed and edited. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the National Natural Science Foundation of China, grant numbers 12172241, 11972241, 12272248, and 11802193; and the Qing Lan Project of colleges and universities in Jiangsu Province.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Zhu, Z.X.; Zhou, Q.Z.; Yin, J.S. Theoretical Mechanics (II); Peking University Press: Beijing, China, 1982. [Google Scholar]
  2. Huang, Z.D.; Zhong, F.E. Engineering System Analytical Mechanics; Higher Education Press: Beijing, China, 1992. [Google Scholar]
  3. Mei, F.X.; Wu, H.B.; Li, Y.M. A Brief History of Analytical Mechanics; Science Press: Beijing, China, 2019. [Google Scholar]
  4. Zhao, Y.Y. New integral variational principle of mechanics. Acta Mech. Sin. 1989, 21, 101–106. [Google Scholar]
  5. Li, J.B.; Zhao, X.H.; Liu, Z.R. Generalized Hamiltonian System: Theory and Its Applications; Science Press: Beijing, China, 2007. [Google Scholar]
  6. Mei, F.X.; Shi, R.C.; Zhang, Y.F. Dynamics of Birkhoffian System; Beijing Institute of Technology Press: Beijing, China, 1996. [Google Scholar]
  7. Podlubny, I. Fractional Differential Equations; Academic Press: New York, NY, USA, 1999. [Google Scholar]
  8. Magin, R.L. Fractional Calculus in Bioengineering; Begell House Publisher: Danbury, CT, USA, 2006. [Google Scholar]
  9. Riewe, F. Nonconservative Lagrangian and Hamiltonian mechanics. Phys. Rev. E 1996, 53, 1890–1899. [Google Scholar] [CrossRef] [PubMed]
  10. Riewe, F. Mechanics with fractional derivatives. Phys. Rev. E 1997, 55, 3581–3592. [Google Scholar] [CrossRef]
  11. Song, C.J.; Agrawal, O.P. Hamiltonian formulation of systems described using fractional singular Lagrangian. Acta Appl. Math. 2021, 172, 9. [Google Scholar] [CrossRef]
  12. Baleanu, D.; Agrawal, O.P. Fractional Hamilton formalism within Caputo’s derivative. Czech. J. Phys. 2006, 56, 1087–1092. [Google Scholar] [CrossRef]
  13. Rabei, E.M.; Nawafleh, K.I.; Hijjawi, R.S.; Muslih, S.I.; Baleanu, D. The Hamilton formalism with fractional derivatives. J. Math. Anal. Appl. 2007, 327, 891–897. [Google Scholar] [CrossRef]
  14. Klimek, M. Lagrangean and Hamiltonian fractional sequential mechanics. Czech. J. Phys. 2002, 52, 1247–1253. [Google Scholar] [CrossRef]
  15. Herzallah, M.A.E.; Baleanu, D. Fractional-order EulerLagrange equations and formulation of Hamiltonian equations. Nonlinear Dynam. 2009, 58, 385–391. [Google Scholar] [CrossRef]
  16. Muslih, S.I.; Baleanu, D. Hamiltonian formulation of systems with linear velocities within Riemann-Liouville fractional derivatives. J. Math. Anal. Appl. 2005, 304, 599–606. [Google Scholar] [CrossRef]
  17. Agrawal, O.P.; Muslih, S.I.; Baleanu, D. Generalized variational calculus in terms of multi-parameters fractional derivatives. Commun. Nonlinear. Sci. Numer. Simulat. 2011, 16, 4756–4767. [Google Scholar] [CrossRef]
  18. Nawafleh, K.I.; Hijjawi, R.S. Hamilton formulation of systems with Caputo’s fractional derivatives for continuous systems. Jordan J. Phys. 2011, 4, 87–90. [Google Scholar]
  19. Agrawal, O.P. Generalized variational problems and EulerLagrange equations. Comput. Math. Appl. 2010, 59, 1852–1864. [Google Scholar] [CrossRef]
  20. Noether, A.E. Invariante variationsprobleme. Kgl. Ges. Wiss. Nachr. Göttingen. Math. Physik. 1918, 2, 235–257. [Google Scholar]
  21. Mei, F.X.; Wu, H.B.; Zhang, Y.F. Symmetries and conserved quantities of constrained mechanical systems. Int. J. Dynam. Control 2014, 2, 285–303. [Google Scholar] [CrossRef]
  22. Mei, F.X.; Wu, H.B. Dynamics of Constrained Mechanical Systems; Beijing Institute of Technology Press: Beijing, China, 2009. [Google Scholar]
  23. Mei, F.X. Analytical Mechanics (II); Beijing Institute of Technology Press: Beijing, China, 2013. [Google Scholar]
  24. Zhao, Y.Y.; Mei, F.X. Symmetry and Invariant of Mechanical Systems; Science Press: Beijing, China, 1999. [Google Scholar]
  25. Fu, J.L.; Chen, B.Y.; Chen, L.Q. Noether symmetries of discrete nonholonomic dynamical systems. Phys. Lett. A 2009, 373, 409–412. [Google Scholar] [CrossRef]
  26. Liu, D. Noether’s theorem and its inverse of nonholonomic nonconservative dynamical systems. Sci. China (Ser. A) 1991, 34, 419–429. [Google Scholar]
  27. Zhang, Y.; Zhai, X.H. Noether symmetries and conserved quantities for fractional Birkhoffian systems. Nonlinear Dynam. 2015, 81, 469–480. [Google Scholar] [CrossRef]
  28. Zhou, Y.; Zhang, Y. Noether’s theorems of a fractional Birkhoffian system within Riemann-Liouville derivatives. Chin. Phys. B 2014, 23, 124502. [Google Scholar] [CrossRef]
  29. Song, C.J. Noether symmetry for fractional Hamiltonian system. Phys. Lett. A 2019, 383, 125914. [Google Scholar] [CrossRef]
  30. Song, C.J. Noether and Lie symmetry for singular systems involving mixed derivatives. Symmetry 2022, 14, 1225. [Google Scholar] [CrossRef]
  31. Bourdin, L.; Cresson, J.; Greff, I. A continuous/discrete fractional Noether’s theorem. Commun. Nonlinear Sci. Numer. Simulat. 2013, 18, 878–887. [Google Scholar] [CrossRef]
  32. Frederico, G.S.F.; Lazo, M.J. Fractional Noether’s theorem with classical and Caputo derivatives: Constants of motion for nonconservative systems. Nonlinear Dynam. 2016, 85, 839–851. [Google Scholar] [CrossRef]
  33. Jia, Q.L.; Wu, H.B.; Mei, F.X. Noether symmetries and conserved quantities for fractional forced Birkhoffian systems. J. Math. Anal. Appl. 2016, 442, 782–795. [Google Scholar] [CrossRef]
  34. Malinowska, A.B. A formulation of the fractional Noether-type theorem for multidimensional Lagrangians. Appl. Math. Lett. 2012, 25, 1941–1946. [Google Scholar] [CrossRef]
  35. Zhang, H.B.; Chen, H.B. Noether’s theorem of fractional Birkhoffian systems. J. Math. Anal. Appl. 2017, 456, 1442–1456. [Google Scholar] [CrossRef]
  36. Jin, S.X.; Zhang, Y. Noether conservative quantity for generalized Chaplygin systems on time scales. Indian J. Phys. 2019, 93, 883–890. [Google Scholar] [CrossRef]
  37. Martins, N.; Torres, D.F.M. Noether’s symmetry theorem for nabla problems of the calculus of variations. Appl. Math. Lett. 2010, 23, 1432–1438. [Google Scholar] [CrossRef]
  38. Tian, X.; Zhang, Y. Noether symmetry and conserved quantity for Hamiltonian system of Herglotz type on time scales. Acta Mech. 2018, 229, 3601–3611. [Google Scholar] [CrossRef]
  39. Zhai, X.H.; Zhang, Y. Noether symmetries and conserved quantities for fractional Birkhoffian systems with time delay. Commun. Nonlinear Sci. Numer. Simulat. 2016, 36, 81–97. [Google Scholar] [CrossRef]
  40. Sahoo, S.; Ray, S.S. Lie symmetries analysis and conservation laws for the fractional Calogero–Degasperis–Ibragimov–Shabat equation. Int. J. Geom. Methods Mod. Phys. 2018, 15, 1850110. [Google Scholar] [CrossRef]
  41. Sahoo, S.; Ray, S.S. The conservation laws with Lie symmetry analysis for time fractional integrable coupled KdV–mKdV system. Int. J. Non-linear Mech. 2018, 98, 114–121. [Google Scholar] [CrossRef]
  42. Sahoo, S.; Ray, S.S. Invariant analysis with conservation laws for the time fractional Drinfeld–Sokolov–Satsuma–Hirota equations. Chaos Solitons Fractals 2017, 104, 725–733. [Google Scholar] [CrossRef]
  43. Sahoo, S.; Ray, S.S. Analysis of Lie symmetries with conservation laws for the (3 + 1) dimensional time-fractional mKdV–ZK equation in ion-acoustic waves. Nonlinear Dyn. 2017, 90, 1105–1113. [Google Scholar] [CrossRef]
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Wang, C.; Song, C.-J. Research on the Symmetry of the Hamiltonian System under Generalized Operators. Symmetry 2023, 15, 973. https://doi.org/10.3390/sym15050973

AMA Style

Wang C, Song C-J. Research on the Symmetry of the Hamiltonian System under Generalized Operators. Symmetry. 2023; 15(5):973. https://doi.org/10.3390/sym15050973

Chicago/Turabian Style

Wang, Cai, and Chuan-Jing Song. 2023. "Research on the Symmetry of the Hamiltonian System under Generalized Operators" Symmetry 15, no. 5: 973. https://doi.org/10.3390/sym15050973

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop