Talk:Viscosity solution

Front evolution?

What does 'front evolution' mean? Is it a concept from fluid dynamics? Could someone knowledgeable provide an appropriate link please? --Rinconsoleao (talk) 14:03, 9 June 2008 (UTC)[reply]

Front evolution or front propagation is quite general, it applies to optics, to the simulation of combustion and even to image recognition. Souganidis has a book about it http://www.springerlink.com/content/945754087q296357 . It occurs in many nonlinear PDE problems where there are two areas of space separated by a surface (the front) and that front can move. Encyclops (talk) 22:57, 10 June 2008 (UTC)[reply]

Uniqueness of solution

I was just wondering about the uniqueness of the viscosity solution. Most PDEs can be proven to have a unique solution. What about the viscosity solution? Are they unique, or are there multiple viscosity solutions to a given PDE? (this will probably depend on the PDE in question, but some info on it would be appreciated).