Page 124 - IJOCTA-15-1
P. 124

D. Kasinathan et.al. / IJOCTA, Vol.15, No.1, pp.103-122 (2025)

            By Lemma 5 and equation (11), we have
                         ˜
                    p
            E∥x(ς)∥ ≤ M 2 e  −ως ,  ς ≥ −r, ω ∈ (0, σ 1 Λ σ 2 ),  ∂  2 h
                                                               =     Z(ς, τ) − ˆa 1 (ς, Z(ς − ξ, τ),
            where                                                ∂ς 2
             ˜

                                                   M g (1 +
            M 2 = max M 1 + M 2 , M 3 := 8      p−1 ¯  p      Z ϑ
                                                                                     i
               p           p−1 p  1−p   p        p               ˆ a 2 (ς, ϑ, Z(ϑ − ξ, τ))dϑ) + ˆa 3 (ς, Z(ς − ξ, τ),
                               2  2     f
            M σ 1 ), M 4 := 8  a β    [L (1 + M σ 2 )], M 5 :=
                          p
                 a C p β
                           L G ,
            8 p−1 p  ˜  1− 2 ¯  	                             0
                  2     2                                      ϑ
                                                              Z
                                                                                                         dw(ς)
                                                                 ˆ a 4 (ς, ϑ, Z(ϑ − ξ, τ))dϑ) + ˆa 5 (ς, ϑ, Z(ϑ − ξ, τ))
            where ω is a positive root of the equation                                                    dς
                                                              0
                                                                        H
                                                              + ˆa 6 (ς)dB , 0 ≤ τ ≤ π, ς ̸= ς k ,
                                                                        Q
                                            ∞
                         e ωr        e ωr   X
                ωr                                                                                       (12)
            M 3 e +M 5        +M 6        +    (b k +d k ) = 1.
                        σ 2 − ω    σ 1 − ω                    subject to the following initial conditions
                                            k=1
                                      ∞      p
                                p−1 p  P    1  q
            Here         =     8   a      L     ;        =    Z(ς, 0) = Z(ς, π) = 0; ς ∈ J
                   b k
                                    1       k      d k
                                       k=1                     ∂
                    ∞     p                                   Z(0, ξ) = x 1 (ξ), ξ ∈ [0, π]
             p−1 p   P   2  q                                 ∂ς
            8    a      L    .
                  2      k
                    k=1                                                   ˆ a 7  +
                                                              ∆Z(ς k , ·)(τ) =  Z(ς , τ), ς ̸= ς k , k = 1, m
                                                                          k 2  k
            Now, we take
                                                                                −
                                                               ′
                                                              ∆ Z(ς k , ·)(τ) =  ˆ a 8  Z(ς , τ), t ̸= ς k , k = 1, m
                                                                           k 4  k
                         p
                                        ˜
                                    ˜
                  E∥x(ς)∥ ≤ max{M 1 , M 2 }e −ως , ς ≥ 0.            X   π
                                                                      n Z
                                                              Z(ς, ξ) −    q i (ς, ξ)Z(ς i , ξ)dξ = φ(ς, ξ), ς ∈ J 0 , ξ ∈ [0, π],
                                                                      i=1
                                                                         0
                                                              where ˆa i > 0, (i = 1, 2, . . . , 8) and nonlinear con-
            Thus, the mild solution of (1) is exponentially
            stable in the p th  moment sense.                 tinuous functions are defined by
            Remark 2. Stability critical is a property of the         Z ς
            dynamical systems for investigation in various do-  g(ς, x ς ,  σ 1 (ς, ϑ, x ϑ )dϑ)
            mains.   In fractional order systems, there are
                                                                      0
            many challenging and unsolved problems related
                                                                                    ϑ
            to stability theory. The stability analysis has been                   Z
            performed by the convergence of solutions for frac-  = ˆa 1 (ς, Z(ς − ξ, τ),  ˆ a 2 (ς, ϑ, Z(ϑ − ξ, τ))dϑ),
            tional order differential and trajectories of dy-                      0
            namical systems under small perturbations of the          Z ς
            initial condition. Recently, different types of sta-  f(ς, x ς ,  σ 2 (ς, ϑ, x ϑ )dϑ)
            bility such as Mittag-Leffler stability, generalized
                                                                       0
            Mittag-Leffler stability, Ulam stability, and Ulam-                     ϑ
                                                                                   Z
            Hyers stability have been discussed. The exponen-
                                                                = ˆa 3 (ς, Z(ς − ξ, τ),  ˆ a 4 (ς, ϑ, Z(ϑ − ξ, τ))dϑ),
            tial stability cannot be used to characterize the as-
            ymptotic stability of fractional order systems.                        0
                                                                         dw(ς)                       dw(ς)
                                                               G(ς, ϑ, x ϑ )    = ˆa 5 (ς, ϑ, Z(ϑ − ξ, τ))  ,
            5. Example                                                     dς                          dς
                                                                       σ(ς)dB H  = ˆa 6 (ς),
            In this section, we apply the main result for the                Q
            study of the exponential stability for the higher-          I (x ) =   ˆ a 7 , k = 1, m
                                                                          1
                                                                             +
            order FNSIDEs with impulsive noises driven by                k   ς k   k 2
            fBm. In particular, we have to study the follow-              2  +     ˆ a 8
                                                                        I (x ) =     , k = 1, m.
                                                                         k
            ing neutral stochastic partial integro-differential              ς k   k 4
            equations of the form                             Here, dw(ς) is a standard one-dimensional Wiener
                                                              process in a separable Hilbert space H, defined
                    ∂  h  ∂                                   on a stochastic basis (Ω, F ς , P). B (ς) is a fBm
                                                                                               H
                          Z(ς, τ) − ˆa 1 (ς, Z(ς − ξ, τ),                                      Q
                                                                                    1
                   ∂ς ∂ς                                      with Hurst index H ∈ ( , 1) which is independent
                                                                                    2
                    ϑ                                         of w(ς). To rewrite (12) into abstract form (1),
                   Z
                                              i                                             2
                                                              we consider the space H = L ([0, π]) with the
                      ˆ a 2 (ς, ϑ, Z(ϑ − ξ, τ))dϑ)                                 q
                                                              norm ∥ · ∥. Z n (x) =   2  sin(nx), n = 1, 2, . . . ,
                   0                                                                  π
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