0000000000395167

AUTHOR

Coloma Ballester

0000-0001-6535-7367

showing 2 related works from this author

Minimizing total variation flow

2000

We prove existence and uniqueness of weak solutions for the minimizing total variation flow with initial data in $L^1$. We prove that the length of the level sets of the solution, i.e., the boundaries of the level sets, decreases with time, as one would expect, and the solution converges to the spatial average of the initial datum as $t \to \infty$. We also prove that local maxima strictly decrease with time; in particular, flat zones immediately decrease their level. We display some numerical experiments illustrating these facts.

Dirichlet problem35K90Partial differential equationMeasurable functionApplied MathematicsMathematical analysis35B40Existence theorem35K65General Medicine35D0535K60Maxima and minimaUniqueness theorem for Poisson's equation35K55Neumann boundary conditionUniquenessAnalysisMathematics
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The Dirichlet problem for the total variation flow

2001

Suppose that Ω is an open bounded domain with a Lipschitz boundary. The purpose of this chapter is to study the Dirichlet problem $$ \left\{ \begin{gathered} \frac{{\partial u}} {{\partial t}} = div\left( {\frac{{Du}} {{\left| {Du} \right|}}} \right)in Q = \left( {0,\infty } \right) \times \Omega , \hfill \\ u\left( {t,x} \right) = \phi \left( x \right)on S = \left( {0,\infty } \right) \times \partial \Omega , \hfill \\ u\left( {0,x} \right) = u_0 \left( x \right)in x \in \Omega \hfill \\ \end{gathered} \right. $$ (5.1) where u0 ∈ L1(Ω) and ϕ ∈ L1 (∂Ω). This evolution equation is related to the gradient descent method used to solve the problem $$ \begin{gathered} Minimize \int {_\Omega \lef…

Dirichlet problemMathematical analysisBoundary (topology)Dirichlet's energyOmegaCombinatoricssymbols.namesakeFlow (mathematics)Dirichlet's principleDomain (ring theory)Evolution equationsymbolsAnalysisMathematics
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