American Journal of Systems and Software, 2016, Vol. 4, No. 2, 57-68 Available online at http://pubs.sciepub.com/ajss/4/2/5 ©Science and Education Publishing DOI:10.12691/ajss-4-2-5 Existence and Stability of Mixed Stochastic Fractional Order Differential Inclusion Equations via Cosine Dynamical System Salah H Abid, Sameer Q Hasan * , Zainab A Khudhur Department of Mathematics, College of Education Almustansryah University *Corresponding author: dr.sameer_kasim @yahoo.com Abstract In this paper, we shall consider the existence and stability of stochastic fractional order differential inclusion nonlinear equations in infinite dimensional space by mixed fractional Brownian motion in Hilbert space H. Keywords: Neutral mixed stochastic fractional order differential inclusion equations, existence, stability, via cosine dynamical system with fractional derivative as component in nonlinear functions 0<α, β<1 Cite This Article: Salah H Abid, Sameer Q Hasan, and Zainab A Khudhur, “Existence and Stability of Mixed Stochastic Fractional Order Differential Inclusion Equations via Cosine Dynamical System.” American Journal of Systems and Software, vol. 4, no. 2 (2016): 57-68. doi: 10.12691/ajss-4-2-5. 1. Introduction In this article we study the neutral second- order abstract differential inclusion problem () () ( ) [ ] () () () ( ) () () ( ) 1 2 ´ , , , , , . H d x t gtxt Ax t F txt D xt dw F txt D xt dw α β + + (3.1) () 0 0 x x = () 1 0 ,0 , 1, 1. 2 x x H αβ = < < Where : → is a generator of cosine semigroup on a Hilbert space (, ‖∙‖), {(): ≥ 0} and { (): ≥ 0} are −valued Brownian motion and fractional Brownian motion respectively with afinit trace nuclear covariance operator >0 . 1 , 2 , satisfy suitable conditions that will be established later on. The random variable 0  ‖ 0 2 < . This problem has been studied in case 0< , ≤ 1 , ([1,2,3,16]). Well-posedness has been established using different fixed point theorems and the theory of strongly continuous cosine families in Banach spaces. We refer the reader to [27,28] for a good account on the theory of cosine families. The theory of integro-differential equations or inclusions has become an active area of investigation due to their applications in the fields such as mechanics, electrical engineering, medicine biology, ecology and so on. On can see ([7,8,25] and references therein). Several authors have established the existence results of mild solutions for these equations ([4,5,21,24]). In addition, the nonlinear integro- differential equations with resolvent operators serve as an abstract formulation of partial integro-differential equations that arise in many physical phenomena. One can see [15] and references therein. The deterministic models often fluctuate due to noise, which is random or at least appears to be so. Therefore, we must move from deterministic problems to stochastic problems. As the generalization of classic impulsive integro-differential equations or inclusions, impulsive neutral stochastic functional integro-differential equations or inclusions have attracted the researchers great interest. And some works have done on the existence results of mild solutions for these equations (see [17,26] and references therein). To the best of our knowledge, there is no work reported on the existence of mild solutions for the impulsive neutral stochastic functional integro-differential inclusions with nonlocal initial conditions and resolvent operators, and the aim of this paper is to close the gap. In this paper, motivated by the previously mentioned papers, we will study this interesting problem. Sufficient conditions for the existence are given by means of the fixed point theorem for multi-valued mapping due to Dhage [11] and the fractional power of operators. Especially, the known results appeared in [9,10] are generalized to the stochastic settings. An example is provided to illustrate the theory. We refer the reader to Da prato and Zabczyk [12]. throughout the paper (, . ) ( , . )denote two real separable Hilbert spaces. In case without confusion, we just use .,. for the inner product and . for the norm. Let (, , ; ) (={()} ≥ 0 ) be complete filtered probability space satisfying that 0 contains all -null sets of . An -valued random variable is an -measurable function (): → and the collection of random variables ={(, ): →⧵∈} is called a stochastic process. Generally, we just write x(t) instead of (, ) and (): → in the space of S. Let { } =1 be a complete orthonormal basis of . Suppose that {(): ≥ 0}