# Difference between revisions of "Quasilinear"

From DispersiveWiki

Jump to navigationJump to searchm (typo, QNLW link) |
|||

Line 8: | Line 8: | ||

one can place such equations in the slightly simpler form | one can place such equations in the slightly simpler form | ||

<center><math>F( v) D^k v = G( v, Dv, \ldots, D^{k-1} v )</math></center> | <center><math>F( v) D^k v = G( v, Dv, \ldots, D^{k-1} v )</math></center> | ||

− | + | though this trick comes at the cost of lowering the regularity of the fields. | |

Quasilinear equations are more nonlinear than [[semilinear]] ones, but less nonlinear than [[fully nonlinear]] equations. | Quasilinear equations are more nonlinear than [[semilinear]] ones, but less nonlinear than [[fully nonlinear]] equations. | ||

+ | |||

+ | ==See also== | ||

+ | [[QNLW|Quasilinear nonlinear wave (QNLW)]] | ||

[[Category:Concept]] | [[Category:Concept]] |

## Latest revision as of 15:35, 12 December 2007

A **quasilinear equation** is an equation of the form

which is linear (and nontrivial) in the top order terms . Thus a quasilinear equation takes the schematic form

By differentiating this equation up to times and working with the system of fields , one can place such equations in the slightly simpler form

though this trick comes at the cost of lowering the regularity of the fields.

Quasilinear equations are more nonlinear than semilinear ones, but less nonlinear than fully nonlinear equations.