Difference between revisions of "Dissipative system"
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''D-system, limit-bounded system'' | ''D-system, limit-bounded system'' | ||
A system of ordinary differential equations | A system of ordinary differential equations | ||
− | + | $$ | |
+ | \dot{x} = f ( t , x ) ,\ x \in \mathbf R ^ {n} , | ||
+ | $$ | ||
− | with continuous right-hand side, whose solutions | + | with continuous right-hand side, whose solutions $ x ( t ; t _ {0} , x _ {0} ) $ |
+ | satisfy the properties of uniqueness and infinite extendability to the right, and for which there exists a number $ \rho > 0 $ | ||
+ | such that for any solution $ x ( t ; t _ {0} , x _ {0} ) $ | ||
+ | it is possible to find a moment in time $ T ( t _ {0} , x _ {0} ) \geq t _ {0} $ | ||
+ | such that | ||
− | + | $$ | |
+ | \| x ( t ; t _ {0} , x _ {0} ) \| | ||
+ | < \rho \ \textrm{ for all } t \geq T ( t _ {0} , x _ {0} ) . | ||
+ | $$ | ||
− | In other words, each solution is immersed, sooner or later, in a fixed sphere < | + | In other words, each solution is immersed, sooner or later, in a fixed sphere $ \| x \| < \rho $. |
+ | An important particular case of a dissipative system are the so-called systems with convergence, for which all solutions $ x ( t ; t _ {0} , x _ {0} ) $ | ||
+ | are defined for $ t _ {0} \leq t < \infty $ | ||
+ | and, in addition, there exists a unique bounded solution on the entire axis which is asymptotically stable in the large. Such systems have been thoroughly studied (see, for example, [[#References|[1]]]). | ||
====References==== | ====References==== | ||
<table><TR><TD valign="top">[1]</TD> <TD valign="top"> V.A. Pliss, "Nonlocal problems of the theory of oscillations" , Acad. Press (1966) (Translated from Russian)</TD></TR><TR><TD valign="top">[2]</TD> <TD valign="top"> B.P. Demidovich, "Lectures on the mathematical theory of stability" , Moscow (1967) (In Russian)</TD></TR></table> | <table><TR><TD valign="top">[1]</TD> <TD valign="top"> V.A. Pliss, "Nonlocal problems of the theory of oscillations" , Acad. Press (1966) (Translated from Russian)</TD></TR><TR><TD valign="top">[2]</TD> <TD valign="top"> B.P. Demidovich, "Lectures on the mathematical theory of stability" , Moscow (1967) (In Russian)</TD></TR></table> | ||
− | |||
− | |||
====Comments==== | ====Comments==== | ||
− | |||
====References==== | ====References==== | ||
<table><TR><TD valign="top">[a1]</TD> <TD valign="top"> J.K. Hale, "Ordinary differential equations" , Wiley (1980)</TD></TR></table> | <table><TR><TD valign="top">[a1]</TD> <TD valign="top"> J.K. Hale, "Ordinary differential equations" , Wiley (1980)</TD></TR></table> |
Latest revision as of 19:36, 5 June 2020
D-system, limit-bounded system
A system of ordinary differential equations
$$ \dot{x} = f ( t , x ) ,\ x \in \mathbf R ^ {n} , $$
with continuous right-hand side, whose solutions $ x ( t ; t _ {0} , x _ {0} ) $ satisfy the properties of uniqueness and infinite extendability to the right, and for which there exists a number $ \rho > 0 $ such that for any solution $ x ( t ; t _ {0} , x _ {0} ) $ it is possible to find a moment in time $ T ( t _ {0} , x _ {0} ) \geq t _ {0} $ such that
$$ \| x ( t ; t _ {0} , x _ {0} ) \| < \rho \ \textrm{ for all } t \geq T ( t _ {0} , x _ {0} ) . $$
In other words, each solution is immersed, sooner or later, in a fixed sphere $ \| x \| < \rho $. An important particular case of a dissipative system are the so-called systems with convergence, for which all solutions $ x ( t ; t _ {0} , x _ {0} ) $ are defined for $ t _ {0} \leq t < \infty $ and, in addition, there exists a unique bounded solution on the entire axis which is asymptotically stable in the large. Such systems have been thoroughly studied (see, for example, [1]).
References
[1] | V.A. Pliss, "Nonlocal problems of the theory of oscillations" , Acad. Press (1966) (Translated from Russian) |
[2] | B.P. Demidovich, "Lectures on the mathematical theory of stability" , Moscow (1967) (In Russian) |
Comments
References
[a1] | J.K. Hale, "Ordinary differential equations" , Wiley (1980) |
Dissipative system. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Dissipative_system&oldid=46751