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Existence and Uniqueness of the Solutions to Neutral
Stochastic Differential Equations with Infinite Delay
1
Mo Chi , Luo Jiaowan
School of Mathematics and Information Sciences, Guangzhou University, Guangzhou, (510006)
E-mail:254994344@qq.com
Abstract
In this paper, we consider neutral stochastic differential equations with infinite delay. Existence and
uniqueness of the solutions are obtained under non-Lipschitz condition with Lipschitz condition being
considered as a special case. Our results generalize the known results.
Keywords: Existence; Uniqueness; Neutral stochastic differential equations.
1. Introduction
Neutral delay differential equations are often used to describe the dynamical systems which not
only depend on present and past states but also involve derivatives with delays. Practical examples of
neutral delay differential system include population ecology [3], and other engineering systems [2]. For
neutral stochastic delay differential equations, we can refer to [4,5,6].
In the recent years, there is an increasing interest in stochastic differential equations with infinite
delay under less restrictive conditions than Lipschitz condition. e.g. Wei and Wang in [8] discussed
stochastic functional differential equations (SFDEs in short) with infinite delay under uniform
Lipschitz condition and a weakened linear growth condition. Ren, Lu and Xia in [7] obtained the
existence and uniqueness of solutions to SFDEs with infinite delay under non-Lipschitz condition.
Motivated by the works just mentioned, in this paper we will concerned with the existence and
uniqueness of solutions to neutral stochastic differential equations with infinite delay under
non-Lipschitz condition.
The rest of this paper is organized as follows. In section 2, we introduce the basic notations and
definitions. In section 3, we state the results about existence and uniqueness of solutions, and give the
proof of our results.
2. Preliminaries
In this section, we will briefly give some basic notations and definitions.
Let
|.| denote the Euclidean norm in
n
. If
is a vector or a matrix, its transpose is
denoted by
T
A ; if A is a matrix, its Frobenius norm is represented by
|| ( )
T
trace A A=
. Let
12
() ( (), (), , ())
T
m
ttt t
ω
ωω
= L be an
m
-dimensional Brownian motion on a complete
probability space
(,,)F
Ρ with a natural filtration
0
()
ttt
F
≥
(i.e.
0
():
t
Fstst
ω
≤≤),
2
(( ,0], )
d
−∞M denote the family of all
0
t
F -measurable,
d
-value process
() (, )tt
φω
=
,
(,0]t ∈−∞
, such that
0
2
|()|Etdt
φ
−∞
∞
∫
, (( ,0], )
d
CR−∞ denote the
family of bounded continuous
d
-value functions
defined on
(,0]
∞
with norm
0
sup | ( ) |
θ
ψθ
−∞< ≤
=
. Let
0
t be a positive constant and denote
0
[,]JtT
.
In this paper, we are interested in the existence and uniqueness problems of following system
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This work is supported by the Foundation of Guangzhou Education Bureau (Grant No. 08C019)