Invariants and related Liapunov functions for difference equations
Consider the difference equation x n+1 = f(x n , where x n is in R k and f : D → D is continuous where D ⊂ R k . Suppose that I : R k → R is a continuous invariant, that is, I( f(x) ) = I( x ) for every x ∈ D . We will show that if I attains an isolated minimum or maximum value at the equilibrium (f...
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Published in | Applied mathematics letters Vol. 13; no. 7; pp. 1 - 8 |
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Main Author | |
Format | Journal Article |
Language | English |
Published |
Elsevier Ltd
01.10.2000
|
Subjects | |
Online Access | Get full text |
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Summary: | Consider the difference equation
x
n+1 = f(x
n
, where x
n is in
R
k
and
f
: D → D
is continuous where
D ⊂
R
k
. Suppose that
I :
R
k
→
R is a continuous invariant, that is,
I(
f(x)
) = I(
x
)
for every
x
∈ D
. We will show that if
I attains an isolated minimum or maximum value at the equilibrium (fixed) point
p of this system, then there exists a Liapunov function, namely
±(I(
x
) − I(
p))
and so the equilibrium
p is stable. This result is then applied to some difference equations appearing in different fields of applications. |
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ISSN: | 0893-9659 1873-5452 |
DOI: | 10.1016/S0893-9659(00)00068-9 |